Determining ARV from comps that are bigger.

[Baylie Sappir]

Newbie here looking at a wholesale property in Philadelphia that is a shell and needs full rehab. It is a 2 bed 1 bath with 1,008 sqft. The neighborhood is changing for the better, however the renovated comparables are mostly 3/4 bed, 3 bath and double the sqft selling anywhere from 320k to 400 k. My question is how would I figure out the "apples to apples" ARV in a situation like this?