Baby purchase ideas?

Through a series of annoying events in which I was let down for the first time by an ebay seller, I am currently sitting on $20 worth of gift certificates from ebay (which, incidentally, is $10 less than the money I paid for an item I never received) which may expire at some point in the near future.

As much as I would love to spend this money on frivolous fun things (Conversations with Carl Sagan? Heck yes!), I feel that I should use this towards baby acquisitions. However, I have run into two problems:

1. I don't really know where to start, and there are a jillion different categories in the "baby" section of ebay
2. Baby stuff isn't cheap, and $20 doesn't go that far

So is there anything reasonably priced that anyone who has kids can point me towards that they went, "Oh, I definitely needed this!" when they gave birth?

-Kaytlyn