Honestly I would just move on and put that money towards a nice new bike. You have put some good heavy use on that bike so I would suggest taking that knowledge and figure out what you liked and didn't like about it and get something new. It is not a super rare or valuable bike so unless it has some super deep sentimental value it won't really be worth a repair. However there are plenty of great steel bikes out there and plenty of frame builders as well who could build you the bike of your dreams or if you just want another entry level type bike there are tons of those as well. Cues 10 or 11 speed is becoming pretty popular on entry level road bikes and is pretty functional. Or go in a different direction and think about something new?