Much depends on where you live. Finding a used CX bike for under $500 is certainly possible if you're in a place where CX has a decent size following. You want to find someone who is upgrading from an entry-level bike to something better. Just because it's not listed on Craigslist, doesn't mean it's not for sale. Most regions with a quasi-organized CX series will have some kind of an online community (at least a Facebook page). Try reaching out there to see if you can plant the "upgrade bug" in someone's ear
