1998 Mirada Coachmen Fender Skirts

hello we bought a 1998 class a coachman Mirada last year and it had been sitting for about eight years so there's pretty low mileage... but it's got a lot of like heat and sun damage the curtains were falling apart all the upholstery inside was dry rotted anyway make a long story short I think it had some water issues when we were driving it home last year two of the rear fender skirts fell off and what happened was the body of the coach around the wheels had gotten wet and I think there's some rot so the screwsLoosened up and the fender skirts fell off in the road & busted being t brittle plastic..... does everybody replace with original equipment or is there another type of material that can be used I found some fender skirts I think may be a good replacement but they're like $250 apiece