here in florida we charge $500 to $1000 to acid wash a pool and refill it using a filter and re balance the chems
u are probably looking at another $1000 to remove and replace the tiles

Algae and deswamping won't require an acid bath. Other issues may. Acid baths and washes shorten plaster life.

Pricing for tile line repairs can be a couple hundred or a couple thousand. It depends on the severity. Complete replacement will require draining since debris from the demolition can't be effectively captured as it's knocked off. Tile and the labor costs will vary. Some states have higher costs of doing business.

Popped tiles aren't always due to winter water level issues. The joint between the deck and pool's coping not being sealed can allow water to get wicked in and weakening the bond of the thin set mortar and the tile. This wicking can also effect the coping's bond to the beam.

Hollow sounds can be heard when using a wooden club to lightly tap the top of the coping. It makes a distinctive sound when the coping's bond is loose. Don't be surprised.

Winterized pools can't be properly and professionally inspected. Some may opt for asking funds to be left in escrow to cover unseen but specifically defined issues that wouldn't be found until the pool is opened in Spring. Realtors and lawyers hate this as it can complicate transactions.

I wish you luck. Deswamping is not a big problem. Unseen issues may be. I would worry more about that but it's not likely to make potential "Dream House" disregarded if you allow for any potentials.

Scott

Make the owner pay for the clean up and have it inspected heavily. That smells like a money pit.

It sounds like having the owner handle the clean up would be a smart choice and do check not only the pool but the surrounding areas as well for anything odd.

I recently was involved in brining a pool "back to life" after the previous owner let it sit for almost two years uncovered. It was nothing but algae soup.

However, with some hardwork and about $500-1000 in pool chemicals (The cost was this high partially because I was learning what would work and what wouldn't) I was able to it cleaned up. I've enjoyed it multiple time since without any issues.

A couple other things that might be worth checking if at all possible is whether the pool is stained or not, as well as the condition of the pump, filter, and other systems. These can get expensive fast to get cleaned up.

Good Luck