$550ish is around the price range of a type 56-1. Think reliable V3 mechbox all steel construction, steel side folding stock polymer furniture.
The only person I know that doesn't like his Type 56-2 complains about the weight and the folding stock button sometimes getting stuck. Other than that it's accurate and has descent range.
If the Type 56-2 is out of your price range you can always go for SRC's aluminum body AKs or the Newer CYMA/Echo one Steel AKM. If you are an AR fanboy can't go wrong with a full metal Kings arm M4 they seem to be pretty popular. Again choosing your gun will depend on what you prefer.
Don't forget to factor in the cost of spare magazines, Batteries, BB loader, sling, a means of carrying magazines, Protective gear goggles, mouth protection, bbs, etc.
Well that's my 2 cents happy hunting!