You can buy a rustoleum resurfacing kit at Lowe's or HD but I don't think they usually turn out great, or maybe I just haven't seen the results myself (I used one in a rental and it was "okay" but not what I was expecting).

@Mike Lee thanks for resurfacing this!

I replaced a sewer line and resurfaced the parking lot of a townhome community recently.

Do high dollar stuff yourself and refinish/resurface vs replace when possible. 

Wanted to try and find a cost effective solution to making it less of an eyesore for my tenants and future tenants.Have considered Resurfacing, due to large amount of cracks and such but far too expensive for my liking.  

The thrice resurfaced 1960's solid cast iron tub was peeling AGAIN & the old small black & red tile & shower/tub fixtures etc were an antique corroded leaking mess. 

Hi MikeI sold REOs in South Florida - and the cost for completely resurfacing the average pool there was around $3500 - As an aside - I've seen some horrendous looking pools cleaned up beautifully for $500. 

Charge for the repair take photo's prior to work being done.This is damage and they are responsible.. you will always get the OH what's up with the tub look if you don't fixit now.And later you can't take it off the security deposit if you don't do it now.Expect to redo the tub surface in another 4 to 5 years as the resurfacing rarely lasts longer than that.I've had several done and price was about 365.00 for complete tub so I'd check around.

The roof will be replaced, the walls in both units currently have plaster, they will be drywalled and the ceilings need to be resurfaced.

You can get them resurfaced.