I second Ian's comments, fix it yourself. I just did my first weld this year on my burn. It was a little nerve wracking at first, but really is pretty easy. My crack was pretty significant ~6" center hull under the seat, and has held up great. Couple of the suggestions that I got that were key to success on the first attemp were:
1) Start slow and don't get the gun too hut. I used the Harbor Frieght welder (~$80) and had the setting on 5.
2) Best if the welding rod is about 2" longer than the crack.
3) keep the gun moving, ovals between the rod and the boat worked well.
The links provided by Ian have lots of great information. Feel free to give me a call if you want to talk through it. 3oh3 9three1 8756 - Lucas