
My suggestion is since you will be sailing your first cat, you won't be racing much and don't have to worry about class approved parts. Best thing you can do as a sailer is learn how to repair your boat yourself. Make your own new standing rigging, fiberglass repairs, ect. This makes sailing MUCH cheaper (so you can blow that money on $1000 mainsails

Mylar sails are nice, just have to take care of them because mylar is famous for delaminating if stored wet, or left in the sun for a long time. The huge bonus to mylar is that the sail shape is much better, and stays that way. Doesnt stretch like dacron)
There are a lot of good technical forum posts on beachcats about do-it-yourself repairs.