all in the title.
we call them secondhand shops were I am
and if the place sells electrical apliances and game consols then youll probably find one or more
xbox 360s can be as cheap as $300 (even a bit less) in the shops now
so at secondhand places youd be expected to pay around $150-around $250
there not too cheap yet though because its a pretty new consol
It depends on the shop. Some are operated by old people who don't know at all the value of them, which is why you'll see some priced as high as $600 (not kidding!) So it really depends. Look for one on craigslist, as well as diffenent shops in your area.