I've done a couple of large car headliners myself. It's a royal pain for a typical car to get the old headliner out, scrap off the old glue and foam, and get it back in without damaging it.
On the Model 3, it's a piece of cake. It's tiny considering the whole roof is glass, and it's divided in many sections. That makes it a super easy job to recover. It would be a simple DIY arts and crafts project to pull out the pieces, recover with the material of your choice that you buy in bulk, and reinstall. You'd have to be nuts to pay thousands for that job.