The 7770 is a great budget card and for $100 it's a steal. Unfortunately it's just that, a budget card. Read Tom's review
and check out the benchmarks. While the 7770 is faster than the 550 Ti it doesn't scream. If you're not looking to run on Ultra then yes, it's a good deal, especially at $100.
At your resolution High settings will be easily attained, maybe Ultra / Max on the older games.