These are a few of my many eBay secrets, but it's only if you're willing to waste some real time. It's a fun challenge for me, but I have to quit doing it after awhile because it's addictive, unproductive, and self-indulgent. You look under the option for price first (low, of course), and I find that inviduals sell for less than stores. There is an art to placing a bid and off hours are best, but the art is too long to explain here. This is a great secret: look for incorrect listings, but this takes tons of time. Look for patterns where kits are supposed to be listed, and vice versa. People don't spot these so easily, and many times you have the advantage of being the only bidder. Here a couple of El Cheapo kits I'd been admiring that I felt guilty for getting at the prices I paid.
I got a decent start yesterday on a new piece I'd been wanting to do. The finished image is in my sidebar.