https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-prn1/1015698_485029868238234_862068067_o.jpg (link because big picture) Last sunday my MX80 broke without warning . It took a lot of hits, but i never expected the grip to fail on me.
This actually can be repaired and it isn't that hard either. I did it with one of my rackets once and it costed me less than $5 I think. Replacement handles can be purchased from mybadmintonstore.
You are lucky that it was the grip that broke and not the shaft or head, the grip can be repaired (its just wood) and it wouldn't affect the performance of the racket.
I'm actually very thankful for the big Karakal PU grip. The trajectory of the racket was straight towards my girlfriend but the grip thwarted that little scheme . Getting an MX JJS today and i'm probably going to order a new grip off the internet to repair it myself.
Here's an excellent tutorial on handle repair : http://m.instructables.com/id/Fix-your-broken-badminton-racket-handle/