If you don't shop for one that's already flashed to Cricket, you'll save yourself at least $100. You'll have to do the flash job yourself, but odRAB are that the people on these boarRAB can help you flash it better than whatever hole in the wall you may end up buying from.
Your best bet for a low price is to search for bad ESN ones on eBay. I saw brand new ones on there, still in box, for $175 Buy it Now a few weeks back.