To buck the trend and be constructive--
I'd get a used Spyder Victor. You can buy them for $30 or less. Keep it stock except for a new feedneck--the plastic one will break. Get a spring kit, spare cup seals, detents, and spares of every o-ring in the gun. Practice with it and read up on maintenance, but don't take it apart unless you need to fix it. To oil it you can simply put some 3-in-1 in the ASA, put on your tank, and shoot a few times. Works like a charm and is virtually the only maintenance needed.
I recommend the Victor because it's durable, easy to disassemble and repair, parts are easily obtained and there are no electronics to fuss over.
Also, if you're getting a back-up gun, get a gravity hopper as well--electronics will always go haywire when you least expect it.