You can get an FSA Omega triple with MegaExo bottom bracket for around $60 on eBay. That's not a whole lot more than a new chain ring. On the other hand, they recommend that you have your bottom bracket re-faced when you install an external bearing bottom bracket. So maybe it's best to just replace the chain ring. You probably wouldn't feel a huge difference.
I don't think there's a whole lot of advantage to a double crankset unless you're racing. The theory is that they shift better, are easier to setup and maintain and are slightly lighter. While a compact double gives you most of the range of a triple, it's a little less.
Incidentally, you can use a crankset that is marketed as 10-speed with a 9-speed drivetrain.