Where ‘wet rooms’ are concerned, I’d be particularly inclined to hire out anything that connects to the plumbing (it’s going to impact the rest of the house, you probably want to skip the part where the wax ring of the toilet breaks and the toilet falls through the floor to the level below, or leaks behind the tile causing failures inside the wall) and get as good as you can afford in a tile installer - provided you are going simple on the tiles you don’t need an expert in ornately laid out designs using specialty tiles from Italy or where ever. I think people have jumped into getting large format tiles on the shower walls without understanding the unique difficulties involved. The exhaust fan should be a pro too. But after things go in with the more complex stuff you may find you can do floor tiles or screw on the fixtures yourself, even the swapping of lighting is pretty easy (IF you follow the instructions and learn basic safety for electrical - I put up a ceiling fan myself with ZERO previous experience and all it took was connecting like old fan color wire for new fan like color wire, with the box already inside the ceiling. The hardest part was holding the heavy fan body while doing it.) I also prefer to be cautious and patient with home reno stuff - if you have to wait till you can afford to hire out with better skilled pros that’s infinitely better than getting in there to rip out the whole bathroom and realize you’re in over your head and ALSO just messed up/discovered something serious that needs fixing before any new work can happen. Yes, it’s not what most homeowners want to hear when they have reno fever, but do you want fast or do you want excellent?

A lighter shower curtain would allow the sunshine in, so that seems to me to be the best place to start. Since the walls appear to be tiled in the gray, painting won't help. If you wanted to paint what appears to be a new vanity, then violet or lilac may work with the tile and floor. If you do that, get a white and violet/lilac shower curtain. Obviously, I am not a pro!

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.

Seek your answer from a local architect or local competent builder. There is some reason for those steps to be there and you have not provided enough information to determine what that would be. And the realestate agent is blowing it off to sell a house. There may be plumbing issues, there may be floor issues, there may be ceiling issues, there may be roof issues, there may be HVAC issues, there may be window issues, or a number of unforeseen issues. Your answer will not come off the internet, it will come from someone that is able to gather enough pertinent information to leave you with a viable answer.