I, like alot of AGN guys scour the classifieds,ebay and also used store sales. It is a tough situation for a lower budget. For me, best bang for the buck would be an AEA challenger pro .35 or .30. Both put out great power and consistent shots regulated, side lever and can be had used for $500 or so. There are plenty more options out there but not at that price point. Any AEA product will need trigger work, so if that is an issue it changes things. Next would be a benji bulldog, but to me it needs a regulator and trigger work also,and higher price to get go. So with a low budget it gets tricky. The next issue is air. Bigger bore wants more air. GX CS2 compressor is a lifesaver, can be had $200-$250. Manual shutoff, run 1min on and 2min off with the fans going and it will last. Otherwise, $60 handpump does it, but at 400 pumps or more each fill. A small .22 with a hand pump is not a big deal, but bigger bore takes a toll. Beyond the AEA and bulldog you are looking at $1k for a used quality big bore. Air force is in there too, but single shot, many are slug picky and just humongous.