I concur with Kyle’s suggestion. If you go to Artbeats, they email you a free piece of stock footage each month. The libraries themselves can be a bit pricy if you’re on a tight budget, but they are a one-time expense.
Digital juice sends out a daily newsletter, and they have daily specials. Check out the section entitled “Jumpbacks”, and check out what they have to offer. Today’s newsletter had six collections (about 20 clips each) for 9.95 each, and that is also a one-time expense.
You can also create your own in AE, and they’ll cost you nothing 🙂