No one really knows, because I don’t think anyone has ever outlived their Vex.
My FL-8 was old and very used when I took in on trade over 15 years ago. Used it yesterday.
Only once have I needed a repair, and that was all my fault. I left it in a tote on the deck; that night it stormed and the poor FL-8 was completely submerged for 24 hrs. That being said, I called Vexilar (worried about repair vs replace cost) and was asked to send it in. I mailed it on a Thursday, got it back the following Monday-for less than $70, including shipping.