Just because you find the penny stock you like doesn't mean you now have to hurry up and buy the shares. In fact, a superior approach (and by extension superior results) involves keeping an eye on the company for a while. Observe how they typically trade (meaning the average trading volume and volatility), and take time to consider your decision.
If you are set on buying shares, remember that you do not need to buy all of them at once. Investing $2,000 could be done in a single buy, but might serve you better to scale in over a few days in three smaller purchases of $700.