Reno costs on a fully gutted 3/1?

[Pete Milenkovich]

I’m looking at a deal today I’m hopeful I can wholesale. It’s a 2BR/1BA just under 1100 sqft but can be easily converted to a 3/1. It’s currently gutted to the studs and needs all new mechanicals. I’m not sure how to estimate repair costs on a house like this as I’ve never actually done a flip before myself. Is this a deal that should be estimated with a generalized price by sqft  or a different way? Let me know! Thanks