Flat Roof to Pitch Roof Cost vs Return

[Matthew Atchley]

I'm doing my first flip, 3/2/2 brick that has a flat roof that has to be replaced (there are numerous areas inside with ceiling damage/mold). The wholesaler/flipper I bought it from suggests that I invest in adding a pitched roof as I will see a return on the ARV. This being said, I'm seeing that pitch roof bids that I am getting are 2-3 times more expensive, I just can't see the pitch roofing adding 2-3 times more than what I'm going to pay to out a new flat roof on. I don't want to go with my gut and pay to have a flat roof put on and then, have to pay an extra 2-3 times more to have it changed to pitched roof. Any help would be extremely appreciated.