My sister painted, put up personal styled border, all kinds of stuff. Her Realtor came in and told her she needed to make it as neutral as possible, she told her to take down all the borders in the house...lol.
My sister told her that if the people looking didn't like the borders they didn't need her house. I know, she's odd. Anyway, their house didn't sell for near as much as she thought it should.
I think that if you look at this from a buyers perspective you will get a better idea for what you need to do. Go out of your house, take a breath, clear your mind, pretend you are going to look at this house as your own prospective new home. Then go back in.
What do you smell? What assaults your eyes first...lol. What is the atmosphere?
These are what will make the house appealing or appalling.
I think painted every room a neutral color including that yellow bathroom, unless it can be totally toned down, many people do not like yellow, I am one of those unless it is a muted bland shade.
I would look for inexpensive wood vanity units. They do cost a bit but if the house and the bathroom don't flow it takes away from the whole experience.
Do you think that you can do the work yourself? That would save you thousands. My friends recently bought a vanity and counter tops and did it all. It cost them just a few hundred dollars and now the bathroom looks like a magazine layout.