Advice on first property bathroom remodel

[Max Hutchinson]

Hello! I'm getting ready to close on my first property (owner-occupied duplex) and it doesn't need too much remodeling, except the bathrooms. Both bathroom are dated from the 50s, blue/pink tile throughout and looks like some dry rot next to the showerhead Tile looks like its bubbling. Im wondering what would be the best and most inexpensive way to remodel the bathrooms. Im thinking I have to rip up all the old tile and replace the drywall around the shower and install new water-resistant drywall. Now should I install a surround or go with durable/cheap tile? Not looking for anything fancy. What's the most durable for a rental?  Hoping I can stay under $5,000 for two bathrooms is that realistic? I also need to get new flooring. As far as the tub I'm just going to reglaze it. Would appreciate any advice! Thanks. Ive included photos of the two bathrooms for reference.