The crack, in and of itself, looks large but repairable. I don't know the B26 so I can't really tell what I'm looking at. Why did the crack happen? Is there an underlying defect? Was there trauma that could have affected other areas or parts such as the centerboard or pivot hinge?
Then,
What's your comfort level with DIY fiberglass repair? Do you have facilities and time?
If you want to hire it done, you should get a quote for its repair.
It is a good negotiating point. Repairable, but not like fixing spider cracks.
- Will (Dragonfly)