In my humble opinion the better the glass the less power on the ring needed! No glass distortion is key.
Right, what you need is more quality, not more X's. You don't have to spend $500, but you won't find it at $200 either. There are some $400-$500 3-9X40 scopes out there that will do what you need. The greater a scopes power the more important quality is.
At $399 you can get an awful lot of scope with a 3-9X Zeiss Conquest. The new production Leupold VX-2's are a great scope for $100 less. I cannot suggest anything less expensive.