I just bought a H-17, but the Main is delaminating
Same thing has happen to me. After some shopping around I've decided to go with Whirlwind Sails. After a long wait, the main sail has arrived yesterday. The quality is truly outstanding at roughly half a Hobie dealer quote. And this is for a square-head pentex -- a nice upgrade.
I would still give a Hobie dealer a chance. If you can get a Hobie sail at 30-50% more than aftermarket, it is still an acceptable deal.
Another option is to get a used sail. I've seen people selling H17 sails in $300-600
range for a main.