The phrase a penny soul never came to twopence means that extreme meanness never made anyone better off.

These are the earliest occurrences of the phrase that I have found, in chronological order:

1-: From Scrubs, published in Chambers’s Edinburgh Journal (Edinburgh: Published by William and Robert Chambers) of Saturday 12^th October 1844—this essay, by the Scottish publisher and author Robert Chambers (1802-1871), was republished in Essays, Moral and Economic (Edinburgh: W. & R. Chambers; W. S. Orr, London; and J. M‘Glashan, Dublin. 1847):

There is a certain medium between too great and too little liberality of general conduct, which cannot be transgressed far in either direction without injurious consequences. It is bad to be a spendthrift; it is weak to be over-melting and bountiful. But so it is also bad to be unduly solicitous about little savings, or little advantages, or to be ungracefully parsimonious in proportion to one’s circumstances. Such conduct does indeed often appear to be attended with the desired object of accumulation; but when thus successful in one way, it is sure to be injurious in another, in precluding all kindly sympathy from our fellow-creatures, and shutting up many other valuable sources of enjoyment in our own nature. In many cases, however, the apparent success is not justly due to scrubbism, but to qualities of a respectable kind which may have happened to be associated with it, and which would have told better without it. Such at least is the conclusion I am disposed to come to, when I consider how frequently I have seen extreme narrowness in money dealings, and sordidness in expenditure, attended by something like a failure in the great struggles of life. There is an English proverb, that a penny soul never came to twopence; and it is not difficult to see how this should be; for, first, such mean views are very apt to prevent a man from venturing upon perfectly safe enterprises, calculated to be beneficial to him; and, second, they tend to have the effect of disqualifying himself and all connected with him for meeting that public favour on which fortune very much depends.

2-: From Scrubs, by the U.S. author and teacher William Mathews (1818-1909), published in The Athens Post (Athens, Tennessee, USA) of Friday 20^th April 1855:

Meanness, in all its forms, is despicable; but especially so is it in business matters, or when it takes the form of scrubbism. There is no class of men who labor under a more painful delusion than those who practice upon this principle—who, as a moralist says, “think to get the weatherguage [sic] of all mankind by cribbing off sixpences from tradesmen’s bills, and never giving dinners.” It is true such persons meet with a degree of worldly success, sometimes, that justifies their stinginess to themselves; but, nine times out often, it will be found that they have succeeded in spite of that quality, and not on account of it, the natural tendency being to drag them down. They have accumulated wealth, not by their scrubbism, as they chucklingly flatter themselves, but by their industry, perseverance, caution, and other qualities which may have chanced to be associated with their meanness, and which would have ensured far more brilliant results without it. There is an old English proverb, that “a penny soul never came to two-pence;” and when we consider how an extreme narrowness in money dealings disgusts the public, making enemies of those on whose good will fortune greatly depends—and how fatal, too, is such narrowness to that spirit of enterprise which is necessary to a brilliant success—we shall not deem the old saw an exaggeration.

The above-quoted passage appeared as follows in Mercantile Failures, Chapter XIX of Getting on in the World; or, Hints on Success in Life (Chicago: S. C. Griggs, 1874), by William Mathews:

Meanness in all its forms is despicable; but especially in business matters, when it takes the form of scrubbism. There is no class of men who labor under a more perfect delusion than those who practise upon this principle; who never risk a dollar to secure business, unless sure of getting it back again; who never pay a cent for printers’ ink, whether in circulars or advertisements; and who think to get the weather-gauge of all mankind by cribbing sixpences from the bills they incur, passing shillings for quarters, and never giving dinners. It is true such persons meet sometimes with a degree of success which justifies their stinginess to themselves; but in nine cases out of ten it will be found that they have succeeded in spite of that quality, its natural tendency being to drag them down. Their policy is like that of the farmer who sows three pecks of seed where he should sow five, and is recompensed for his leanness of soul by reaping ten bushels of grain instead of fifteen. An English shopkeeper made it a rule never to pay a porter for bringing a burden till the next day; “for,” said he, “while the fellow feels his back ache with the weight, he charges high; but when he comes next day the feeling is gone, and he asks only half the money.” This looks like shrewdness; but never was a policy more suicidal. Selfishness is always self-defeating. When the author of such a sentiment gets wealth, it is not by his scrubbism, as he perhaps fancies, but by his industry, perseverance, caution, and other qualities that chance to be associated with his meanness, and which would insure far more brilliant results without it. There is an old English proverb that “a penny soul never came to two pence”; and when we consider how extreme narrowness in money-dealings disgusts the public, making enemies of those on whose good-will fortune greatly depends, and how fatal, too, is such narrowness to that spirit of enterprise which is necessary to a brilliant success, we shall not deem the old saw an exaggeration.

3-: From Self-Help; with Illustrations of Character and Conduct (London: John Murray, 1859), by the Scottish author Samuel Smiles (1812-1904):

If a man will not be his own friend, how can he expect that others will? Orderly men of moderate means have always something left in their pockets to help others; whereas your prodigal and careless fellows who spend all never find an opportunity for helping anybody. It is poor economy, however, to be a scrub. Narrowmindedness in living and in dealing is generally short-sighted, and leads to failure. The penny soul, it is said, never came to two pence. Generosity and liberality, like honesty, prove the best policy after all.

4-: From Married People’s Money, Chapter XIII of How to be Happy though Married: Being a Handbook to Marriage (London: T. Fisher Unwin, 1886), by the Irish author and Church of England cleric Edward John Hardy (1849-1920):

We should be particular about money matters, but not penurious. The penny soul never, it is said, came to twopence. There is that withholdeth more than is meet, but it tendeth to poverty ¹. People are often saving at the wrong place, and spoil the ship for a halfpenny worth of tar. They spare at the spigot, and let all run away at the bunghole.

¹ This is a quotation from the Book of Proverbs, 11:24:

(King James Version – 1611):
There is that scattereth, and yet increaseth; and there is that withholdeth more then is meete ², but it tendeth to pouertie.

(New King James Version – 1982):
There is one who scatters, yet increases more;
And there is one who withholds more than is right,
But it leads to poverty.

² The adjective meet means suitable or proper—cf. origin of ‘helpmate’: ‘help meet’, i.e. help suitable.