Built gunite pool 4 years ago. Over 3 years, 3 areas the gunite pool had corrosion and rebar near the surface. The builder cut out the rebar behind the corrosion areas and patched the areas. It doesn't look terrible, but I didn't pay for a pool with patches. Over the last year there is no more corrosion. I asked the builder to refinish the pool. He said he would refinish with stonescape minipebble for his cost which is $6000. Is this reasonable ? I thought he should either do it for free or give me a great deal. Is 6000 a good deal for this situation?