I agree with Cpartist"s layout and like moving the closet over as suggested by D M so that bedroom 3 has easier access to the bathroom. Do you have room to have the toilet face the tub and add a linen cabinet next to the toilet? How wide is the tub toilet area?

Sometimes I read these threads and think to myself “oh gee, here go the over-reactors again, they can’t tell for sure it’s not waterproofed, they’re making some assumptions again...” but... yeah... those walls are not ready for tile AT ALL! (Hubby and I have DIYed a handful of gut job bathrooms over the decades) Oh man, I’m really glad you posted so y’all can avoid disaster!

I got the cabinets through Home Depot (20% off) they are not higher end but they have held up extremely well and we’ve been happy with them. I don’t remember the brand, but the color is cognac on maple. They’re standard kitchen cabinets. We got 2 regular drawer banks, 1 extra wide drawer bank, 2 sink cabinets and the closet you can see in the picture for about 1800 w/the discount. We bumped the shower wall 6 inches into the bedroom to make the shower bigger, pulled the cabinets out from the wall a couple of inches to provide more counter top. And curved the edge the counter for interest. Just for fun, this is what we had to start with. The tub was rusted and there were two doors, 1 from the hall & 1 from the master bedroom, we closed up the hall door. I think we got our moneys worth. LOL As for the labor, I found my Contractor through a plumber I had hired to put in a kitchen faucet. I asked if he had someone good he could refer and he referred Matt to me. Matt had his own company but just him and his guys. All of his work was by word of mouth, he didn’t advertise or push for business, he didn’t need to. I think I got fair pricing from him because he didn’t have the overhead a lot of the larger companies might have. He wasn’t the least expensive and he wasn’t the most expensive. Finding someone who was willing to work on our schedule and not having to have it done ASAP is what really helped me to be able to keep our costs at a minium for both labor and materials.

Most likely the joists run parallel to the vanity wall it should allow the plumbing for the toilet to be moved so if that's the case it's doable, you have the room for a 33" vanity with a 15" sink base or to give extra room you can go with a 36" with a 12" base or 42" to give extra room for the toilet if needed.