brand new 11spd ultegra groupset is like $550 online right now, if you can do all the work and install it yourself. new bike with ultegra components start at $1500 and up, again if you shop online. if you go to an LBS, double that to $3000.

comes down to the money you want to spend. if you frame is good and fits you, it'll still be good and fit you. with that said, you've probably gotten your money's worth out of your bike, and nobody would fault you for buying a new one.