If you get away with a few hundred, it seems reasonable. While it's hard to see exactly what was damaged, with minor repair (a few hours) like they apparently did you may have a repeat of the failure. Be gentle with the sail.
I have a "drifter" (130% light air reaching sail) that ripped along a seam from leach to luff (like your genny appears to have done) and I had it repaired two times ($140 and then $250). It failed shortly after each repair. In both repairs they re-stitched the seam that failed and put a patch on the leech a foot or so above and below the point where the seam failed. Obviously, that wasn't enough to solve the problem.
The final solution (so far) was to have the leech re-built top to bottom and the seam reinforced with additional fabric. This repair was about $900, if I remember correctly. Expensive, but still a fraction of what a new sail would cost.
In sail repairs, you often get what you pay for. Good luck with yours.