The "whole thing" is going to be a whole lot more than a few grand and you probably won't get it back on selling. I'd get rid of the wallpaper and replace the cracked vanity top and that's it, unless there is something else bad in there, like a damaged tub, but for that I'd offer a small allowance when listing and not do a whole remodel. You never know what you will find once you start pulling tile off the walls.

Oh, and maybe replace lighting fixture(s). Can't tell about that from the photo, but nothing big, because you won't make it back on the sale 90% of the time.

Remove wallpaper, paint & follow Filipe’s advice re the top. Don’t re-tile.

If you want to remove the wallpaper to brighten it up, that will probably do a lot. There is a special paint you can get to paint over wallpaper. If you don't know what is under the wallpaper, I would recommend that. We removed wallpaper in our kitchen after buying and the walls were a mess. I wish I had painted the wallpaper rather than trying to remove.

people hate wallpaper, so that would benefit you. they also don't like cracks. you can buy a ready made vanity top with the sink, for a few hundred. Pre-fab granite bathroom vanity tops. come in all sizes and colors. here, this place is in chicago. pre fab tops

https://www.factoryplaza.com/granite-marble/vanity-tops/

Or just drop 700 or so for a new vanity that includes the top/sink/and maybe a faucet. look on Craigslists for deals.

paint a light, neutral color, bring in a white fluffy rug (only put down when showing the home) and fluffy white towels. (or taupe or whatever that tile color is)

Thanks for the comments. Do I really want to spend a few hundred bucks on a new top, plus some more to have someone install it? No idea what that would cost - who do you even call to do that? It's a superficial crack.

I would def have someone come in to paint (have touchups to do elsewhere in the house as well), but is it worth removing the wallpaper myself and for those with an opinion on that, do I do the spray on chemical or steam it off? It's drywall.

install it yourself. it's easy. watch a video how to remove paper. you score it, wet it, peel it

here, this place is in chicago. pre fab tops

https://www.factoryplaza.com/granite-marble/vanity-tops/

you asked how to get your bathroom ready to sell. no one wants an icky bathroom. do the minimum. spending 500 is nothing

you and your husband can remove the old top, and replace a new one w/ some caulking and possibly construction adhesive. I don't know what your vanity base is made of. hooking up plumbing is easy. just watch how you undo it, and put it back in reverse. seriously, there are you tube videos for everything nowadays.

I fixed a leak in my fridge from a video

Replace the vanity and top with a low cost option from Home Depot. DH does this with our rentals. When something is new and nutural your eye travels past it onto the next thing.

Remove paper and paint.

We are not at all handy, so I'm 99% certain we would hire someone to install the new top if we went that route.

The sink in our vanity off center because of the layout of the cabinets below. How do I go about getting the countertop cut properly to fit the sink and hardware we have? It's not just a standard plug and play.

In that case, a "quick fix" might look worse than if you just left it and let the buyer remodel the bathroom on their own. You would save yourself $ and work.

I would either (1) replace the whole vanity, sink, counter OR (2) just remove wallpaper/paint/make neat and clean.

I agree with most of the advice - replace the counter top with a prefab or remnant from a stone fabricator in your area. Paint and replace hardware and light fixture. Bathrooms are important to buyers. What they see that needs to be done in a house is more ammunition for them to bring down the price more than necessary due to "needed updates".

if it's off center, then find a remnant piece at a stone fabricators yard and have them cut it to fit your old one. they can probably come out and install it for you too. hooking up the faucet isn't a big deal. sometimes it's worth the little effort to take time and learn some home DIY. Or pay someone. up to you.

If only I had the time, Beth H... Thanks everyone for your responses. I think I know my path!