I've gotten quotes (mostly at the boat show) of 7k and upwards to re-do the fabric on my (16!) interior cushions, re-using the same foam. All new cushions would be >10k from the boat-upholsterers I've talked to (not in the cards).
I'm going to pursue two other (local) options when this rises high enough on my list of things that need doing.
-- a couple of friends who own RVs highly recommend a place called "Hoglunds", in Everett, which apparently does everything from car seats to RV upholstery, and doesn't care if the "RV" is a boat.
-- the young lady who has done a fabulous (and surprisingly reasonable) job of making some covers for Makana says she also makes cushions. So I figure I'll get a quote from her.
I'm planning to re-use the foam - it's dual-density, quite comfortable and in great shape. My only exigent issue is that some of the high-wear cushions (settee, dinette, and the cushion at the nav table) are past the point where darning the thin-spots is a long term solution. I've fixed a couple of weak spots with iron-on patches inside and color-matched thread to take care of any pulling, but I think the clock is ticking more loudly each year. Sewing new covers myself is waaaay outside my skillset (and I can prove it). So at this point I'm thinking I'll get estimates on "main salon" for next year, and do v-berth/q-berth at some later date.
Ambivalent on fabric. I do not like sitting/sleeping on Sunbrella, and as Christian says it isn't needed below, so hoping to find something that is comfy, and wears well. Having said that, the places where the fabric is weakest seem to correspond with where summer sunlight comes in through the hatches/deadlights, so... dunno.
Bruce