So, here's the question should I go ahead and purchase a new sail and hold onto it or wait until my current one finally goes out?
I was in the Caribbean and had sun damage on the main and looked like I needed a new one pronto. But I didn't have any money so I bought a litre (quater gallon) of contact cement glue and a few feet of free sail cloth from the trash.
I sailed from the Caribbean to panama.... 1,000nms
Panama to Galapagos... 1,000 nms
Galapagos to Australia.... 6,000 nms
Bought a new mainsail in Thailand but kept the old one up
Australia to TURKEY,.... ummmm, a long way....
The mainsail finally blew out 40 nms from marmaris, Turkey on the passage from Egypt... a full 2 years after the first patch was done.
So your UV damaged sail might last half a circumnavigation. Mine did!
By the way, sailmakers have a rip-off trick they use to scare you. The fold a bit of your sail between their thumb and forefingers and pull it apart with the leverage of both thumbs along a grain line of the sail. This put a small rip in your sail and they go "AHHH! See? You need a whole new sail!" The reason why this is BS is that the force they use is much higher than the wind and the wind goes across the sail and across the grain not with it.