#3
Regular places - musiciansfriend.com or zzounds.com in the US; gak.co.uk , dolphinmusic.co.uk , coda-music.com etc for the UK ...

You get what you pay for - if you're looking to spend very little money, you're going to get very little quality. If you're looking to get Gibsons etc cheaply, then look at eBay and Craigslist etc.