So I want to build muscle in my abs. What would be good workout equip to buy that doesn't cost over lets say $600 that I can put in my garage? I have a treadmill and I have dumbells for my arms. I do run regularly and that I am toned, but I want to build some muscles in my abs. I don't mean I have to have a super looking six pack but I would like some muscle there to show off.