As I always will say, at any price it's hard to beat a '90s era Crate - Vintage Club 30. Especially the 2x12, maybe the ultimate sleeper amp(h). They get no luv (but by me) and thus you can get them dirt cheap with $$$ left over from your $500 budget to buy more stuff or fix/upgrade the innards, as they can have minor internal maladies from the production line. But they cover so much ground so well, it's worth every penny to get one running in top shape. The only thing they won't do is severe metal, and any pedal remedies that.