Is $7,000 to replace pool liner a fair price?

My pool saga continues. A reputable pool company was hired to help clean up an algae bloom that would not go away due to significant garbage, rocks and debris in the deep end that we could not see due to the algae. During cleaning they decided to drain the pool as it seemed the liner may have some tears. Each pebble on the floor of the shallow end represents the location of a moon-shaped tear consistent with being stabbed with an open-ended pole. The pool guy says it looks like someone was pole vaulting from the shallow end and caused this damage. I'm wondering how come with that many tears we never saw water loss in the 2.5 months since opening the pool. I'm also asking if it's feasible to put a large vinyl patch over all the tears to extend the life of the liner by 1-2 seasons, as I'm looking to sell the property soon and am not prepared for the cost on top of all the repairs already done inside the property.