First time purchasing a quadraplex

[Derrick Jordan]

Im looking at purchasing a quad that listed at 45k but needs total rehab. I know this price is too high. Im want to offer 20k owner is willing to finance.  they are efficiency units 250 sqft. that will cost about 11k per door to rehab. I think i can get at least 275 to 320 a door. I asked a friend about it and he said it not a good deal.  What factors am i not considering?