All the best,
You are asking decorating ideas which is impossible to do without seeing the property. There are no guarantees that whatever you do, the potential buyer will like it. So, just keep it clean, nicely scented and minimal.
In fact the entire remodel should be focused on where that stupid dispenser thingamajig goes.
Just my take on the subject, Dunes
I would first figure out your budget for each bathroom. As mentioned previously, Striping the wall paper and painting will be labor intensive but inexpensive. The condition of the tub and or shower stall is very important as is the vanity sink. There are tub refinishing kits for under fifty dollars and If you have a shower door that is dingy and old, replace it with a curtain. Fixtures can be expensive if your looking for reproductions of antique fixtures, so I would get them as shiny and clean as possible and keep an eye out for salvaged fixtures for sale on the internet. Best of Luck!
Vintage sinks (that's the sink with the 2 skinny legs)are "in vogue" at the moment, so I would agree to simply replace the faucet with a vintage style one if the sink is not a wild color! Definitely keep that sink rather than replacing it with an inexpensive vanity sink. Pedestal style sinks can make a bathroom look bigger.
My advice would be:
Remove the wallpaper
Repaint your bathrooms
Keep the old sink & re-glaze if necessary
Replace the old vanity sink if you can afford it
If you'd like more in depth advice, feel free to contact me & I'll be happy to come by for a free consultation.