eBay for sure. I got my son an $80 catchers glove last season for $25, nice and broken in but not abused. If you spend over $100, you’re not trying hard enough. The secret is, wait for it. Put in a search for the right keywords, eBay will e-mail you when there are matches. Don’t overspend just because something looks good; there’s always something just as good or better a little later.
I would look on Craigslist for a used one. Alot of people go and spend upwards of 75 – 100 dollars and never really use them. Soon there selling them dirt cheap. I would look for either Mizzuno or Rawlings. Once you have the glove, stick a softball in it and place it under your mattress. It will help create a sizable pocket for fielding high fly’s and such.