An investing budget of $300 may not sound like an amount associated with Warren Buffett-type investing. After all, $300 buys less than one B share of Berkshire Hathaway stock.

Nonetheless, smaller-budget investors can still buy shares in most of the components that make up Berkshire's portfolio. Several stocks Buffett owns, such as Floor & Decor Holdings (FND -2.07%), Nu Holdings (NU 0.75%), and Ally Financial (ALLY -0.57%), hold the potential for significant growth over time.

Floor & Decor

One might assume that Home Depot and Lowe's dominate home improvement, but Floor & Decor has shown that enterprises can carve out a niche. Floor & Decor has accomplished that by offering a wider variety of hard flooring, decoratives, and fixtures. Additionally, it has formed the supplier relationships needed to provide product while reducing costs.

As of the end of the first quarter, Floor & Decor has taken the concept to 36 states, opening its 200th store in May. It also plans to open 32 to 35 additional stores this year, so it has maintained a rapid pace of expansion.

Indeed, small investors may only buy one or two shares of this stock at its $115 per share price. However, they will like the $1.1 billion in net sales in the first quarter, a 9% annual increase amid a sluggish economy. And though net income rose only 1% over that time frame due to rising operating expenses, it remains positive at $72 million.

Investors should also like that shares have risen 65% this year. Admittedly, the stock's price-to-earnings (P/E) ratio of 42 may seem a bit pricey considering Floor & Decor's industry and its Q1 income growth. But as the company keeps adding stores, the stock price growth should continue for the foreseeable future.

Nu Holdings

Shares of Nu Holdings currently trade for less than $8 each, so small investors may like that they can buy a lot on a tight budget. But they should like this stock for its massive growth potential. 

NuBank, as its customers know it, provides one of the largest digital banking platforms in the world. But more important is how it has changed finance in Latin America. Latin America is largely a cash-based society, and large percentages of the region's people have neither a bank account nor a credit card. Nu has changed that by issuing the first credit card to nearly 6 million people in its native Brazil, bringing them into the mainstream financial system.

The company also operates in Mexico and recently began operations in Colombia. This rapid expansion should continue as it reaches more of the unbanked in those countries.

In Q1, revenue rose 85% to $1.6 billion over the same quarter last year. Rapid customer expansion fueled this growth as Nu's customer base grew to 79 million, 33% higher than one year ago. The company is also profitable, earning $142 million versus a $45 million loss in the first quarter of 2022.

Amid these increases, Nu stock is up almost 90% this year but still down significantly since its IPO in late 2021. Also, while the price-to-sales (P/S) ratio has increased to 10, it has decreased significantly since late 2021 and early 2022, when it routinely sold for more than 20 times sales. Hence, both the stock price and the sales multiple indicate that there may still be time to profit from this amazing growth story.

Ally Financial

Ally Financial is a digital bank that was spun off from GMAC, the one-time finance arm of General Motors. With no physical branches, it can keep costs low, allowing it to offer higher interest rates and win business from more traditional institutions.

More customers continue to turn to Ally. In the second quarter of 2023, it reported 2.9 million customers, up 16% from one year ago. Its deposits of $154 billion also rose by 10% over the same period.

Admittedly, high interest rates also hurt the bank by reducing demand for new loans. However, it might be an excellent time to buy, especially for income investors. At $1.20 per share, its annual dividend yield is over 4% compared to 1.5% for the S&P 500.

Also, at a $30 per share cost, small investors can buy the stock without needing partial shares. So far, Ally stock is up more than 20% this year. Despite that increase, it sells at a P/E ratio of just 7 versus a high of 17 over the last five years.

That valuation might have helped attract attention from Buffett and his team, and with Ally's growing customer base, it could rise despite increasing interest rates.