£12k spent refurbishing a 152 worth £18k does not a £30k 152 make. More like an £19k 152.
Anyway, you have to feel for the training organisation. Even if their insurance covers all the expenses, there's bound to be some economic problem as a result of this i.e having to lease a plane while a replacement is sought, etc etc. I hope they survive this as so many seem to be going under these days.