Not sure how Pace Arrow does their headliners, but Winnebago has a thin foam layer up there that the headliner is "glued" to and when it starts deteriorating after a number of years it pretty much requires a complete stripping of the whole ceiling and a new headliner and method of attachment done. With Winnies it seems to happen after 10 or 15 years.
A "professional" job for new headliners requires taking out the cabinets, etc. Have seen prices up over 3K area for it.
Some creative owners of RVs find other solutions. Some use standard headliner fabrics while others go with big panel sections. Basically, it's a job.
But, of course, not to stop anybody from getting a good rig just for that problem.