Well, from what I have seen on the forum, some are success stories, some are horror stories. it all depends on:
1. Who does the work
2. The condition of the parts

Always expect to incur some extra costs, a new liner for sure, then probably some plastic parts that got UV dried and crack or break during reinstall, possibly some filter parts since laterals may break during the move of the equipment, possibly a new ladder, and the list goes on.

I would do a thorough inspection of the pool before comitting. Look at the bottom rails - very important - the first component to rust through.

Check the wall for corrosion, especially at the return and skimmer, right down to the floor, if small leaks occur around the gaskets, these areas get eaten.

Check how tight or loose the top rail and verticals are, loose equipment is a sign of stripped screw holes which means you'll have to replace the screws with oversized ones.