I estimated that I would need $100/sq ft to rehab it (around $145k in rehab costs) and the ARV would be around $375k (likely $400 but I want to be a little conservative).

In The Book On Flipping Houses, J Scott says that in order to be a successful house flipper, you need to be a crackerjack estimator.

@Louis Jeffries thanks for the reply, the owner estimate for the one unit rehab is $15k, but if they fix it I’ll be all in at $240k, plus closing.

Hi BP, no matter how many times I re-read David Greene's "Long-Distance Real Estate Investing" book, I still have trouble understanding how to quickly estimate rehab costs when you are looking at multiple different potential deals being sent over from out of state.  

Do you have to pay for an appraisal on your current property or do they use an estimate?

For the main items called out, did you talk to a licensed contractor in that trade to ask them what the estimates to repair would be?

If you ever think repairs are needed, get a free estimate.

Honestly I was worried about this but now being a lender I realize we compete for your business so you just have to shop around to find someone who can make it work for you, just worry about estimating 25% of gross rent goes to expenses outside of PITI and you will be similar to what traditional lenders calculate.

This was an AirBNB guest so I turn it in with pics and a written estimate.

Some rough estimates: Purchase for $200k-225k Rehab:$75k -$100K ARV:$350k-$400k.