Disaster Area Loss

[Kram BergGold]

In MA, we had huge flooding in March. My clients finished basement had 3 feet of water in it. They incured $3,000 to remove the water and humidity and water damaged walls.
Then they paid someone $8,000 to restore the basement to it's prior condition. I read that the loss is limited to the reducton in FMV due to the flood. Any suggestions on how to compute that amount.

[JG EA]

My idea is to see how much less they would have to take off the selling price if they didn't do the basement. As for proof - maybe they could consult a realtor if an appraisal is too expensive.