And the answer is always the same :-) There is no way to accurately do this...too many variables and moving parts, plus it varies too much from one locale to another.You need to find a really good General Contractor and pay him to walk the property with you....over and over....until you feel really comfortable estimating yourself, and that should take years.Alternatively there are online calculators (even one here in the tools section) but I would not rely on them for the reasons listed above.

First stop would be to your local County building permit office and see if it can even be moved. 

I would be happy to get some tips and start building some connections and local professional team.Thanks and Best Regards,Ricky Levy 

I would strongly recommend that you get started locally rather than buying a random property in another state.

Hey @Corby Goade - Just for your own reference since I know you aren't local. 

Hi Alex, my team of agents is local and we wholesale out of the Spokane area. 

We deal with a small local bank.

Even locally, it's been stretch. 

That should help your projections a bitThe 30% is for a local boots-on-ground, full-service company.

Also, you should check with your local municipality to confirm they will allow you to convert the property back to a 2-unit.