Go to this websitehttp://www.trademygun.com
Several on here have endorsed it. I have not bought from them. They have several used guns and it changes by the day. They have a Mini for 200, a BL marq7 for 350, a Proton for 280, a etha for 300, and a ego 06 for 325. Check craigs list and there is always stuff on this site in the B/S/T section.
Your budget really determins what you can get.