This can end up costing thousands more dollars, which can obviously affect your margins. 

Thanks for this info, Rob.

I'd say you need a minimum of $30k for a property at this price, to be safe.  

Quote from @Briant Rivera Arroyo: Hello everyone, I'm relatively new to the Real Estate scene, I've done some research and have concluded I am interested in wholesale to begin my journey.

I am looking to purchase this investment duplex property which was built prior to 1940.

So sorry to hear that you're going thru this. 

only small builder or home are not selling fast enough would consider sell to investor.Anyone in Knoxville could verify this or comment or connect me with builder. 

Basically, from what I've seen (and this is purely anecdotal), they're not really going to go out past one, maybe two miles, unless there simply is no truly comparable property.

Does anyone have specific reference that gives clarity to this situation?

If you are looking to fix and flip, just make sure you look for a 12 month term, non-dutch interest on the rehab funds (this means you do not pay interest on the rehab money until you use it), no prepayment penalty, and avoid any lenders that escrow your payments at closing.