Help - buying used AG Pool

We are currently looking at buying a used AG pool from a friend.

The pool is 9 yrs old, 30 ft round, very well taken care of, w/ original liner.
We as going to pay a small amount but that is worth the deck, chemicals , and odds and ends that are coming with it.

What is ur advice? There is a blemish under the outside wall under the hose that goes for the jet, but it seems structurally sound. The head to the filter is new, but I dot know he brand. I have not seen it with the liner off, so I don't know how the rail looks or the inside of the walls.

If I move it, is a new liner a Must? What else am I not realizing could be a potential issue?

Thanks for any help or input

9 years, the liner's probably not going to want to stretch back into the pool after it's removed and rebuilt; you should count on getting a new one.
Do you think the blemish is rust under the finish - that could be trouble.
You may have trouble locating replacements for buried parts that don't pass muster - If you know where the pool came from, perhaps you can determine the availability of spares before you start.
The expense of installation may exceed the cost of a pool.