Depends upon how you want to go about fixing it. Materials for doing it yourself, from the inside, likely around $100 if you get small enough amounts of resin and can remove & replace the headliner
without it getting damaged. If you want the yard to do it and can’t get at it from the inside (which means having to cut out and re-do the nonskid pattern in the deck
, and match surfaces and colors) perhaps one or two thousand, depending upon how big the repair
actually needs to be. Don’t forget to re-seal the chainplate so it doesn’t happen again.