You may want to take a look at the article here on Tom's about the 4830http://www.tomshardware.com/reviews/4830-radeon-crossfire,2098.html
Otherwise if you can pinch the few extra dollars and break your price set of sub $125 you may want to look into the 4850. I've seen the card for sub $140 after MIR several times and even seen a 9800GTX for the same also.
Otherwise in the sub $125 Nvidia camp you can obtain a 9800GT OC'd easily which will also allow for hardware accelerated PhysX(that's if you play any games that use).
It's rough making GPU decisions with a price constraint, especially with the wide variety available and models separated by a mere $10-$30 in some occasions.But some of us do have financial limitations so why not try to get the most bang for your buck
Cheers! and Happy Hunting