My main and yankee
jib were quoted over $1000 also; that was before gas/diesel prices went through the roof. The sails are heavy Dacron and likely weigh 200# together. My rated sail area is 750 sq ft; but with the high-cut
jib it's probably closer to 700.
I agree that if your sail is getting to the point where it has lost it's shape and/or crispness it might be a good way to go. However I'd first try hand washing it first; you would be amazed what a DIY washing can do to bring some life back into dacron.
I also want to mention that even though they do good work (at least I have heard); the method they use is to wash your sail in a special tumble wash machine. I don't want my relatively un-creased sails getting tumble washed and folded excessively. The folding, creasing and forcing water through the sailcloth is what really breaks down the fibers. It may come back looking like new; but it definitely has gotten some wear/tear from the process. A light hand wash with mild soap and oxy-clean is much less damaging to the sailcloth IMHO.