You'll likely also need fiberglass insulation boards- add $100 per square.

My plans had been to simply install a new fiberglass bath/shower surround, however I don't feel right about just covering up the window like that.

If the cellulose is half price with 25 years warranty than fiberglass.

Does it have laminate flooring rather than hardwood, a granite-tiled counter rather than solid slab, a fiberglass tub rather than tiled.... etc.Here in Denver, a 500-600K property is a touch above average, but back home in Rochester NY that would be WAY above the average, and would thus limit your selling pool. 

It was bank owned and quite a mess—evidently the occupants had to be evicted. 1250 square feet 3-2-2 with half the popcorn removed from the den cathedral ceiling, missing upper kitchen cabinet doors, laminate flooring installed without cutting the door jambs or installing quarter round (so gaps), electrical outlets painted over, a large crack in the one-piece fiberglass tub/shower that had been epoxied over, a broken window and lots of general grime.

We did one where the 1987 OSB they used for flooring was too thin & sagged between the joists.I used the same leveling compound they use for tile work laid a heavy pad & carpeted over the floors.The foyer & hallway we just tiled after the same leveling.If the joists have sagged it's a lot more work ESP if the flooring is the old tongue in groove pine with a subfloor on top.But one of my friends many years ago used Fiber glass shards & resin to fill the voids, but he got it as waste product from the place he worked so it was minimal cost, but it seemed like a lot of work.Good luck

I was picturing a roof deck with fiberglass floor with your first description.

I hire a pluming company replace a shower drain he quoted me at $560.00 He had down the initial inspection and the never mentioned anything about the shower pan being damaged.Today he came out and said that the that t...

If there is a shower vs tub are you putting in a fiberglass pan or tile?

It was white.74 Detomaso Pantera23 bucket T with corvette 327 (fiberglass)23 bucket T with corvette 427 (actual METAL body!)