My thoughts are, Charleston is saturated for a reason! 

Given that the property was worth $390K in its current condition, I saw an opportunity to make the numbers work while keeping my upfront costs low.Instead of increasing my cash offer, I negotiated a $25K down payment with the seller carrying the balance for two years through owner financing.

I might be able to help, but what's the reason your builder is looking to refinance? 

My thinking immediately turned to researching local rental costs per square foot to determine income potential with triple the current square footage.

I wouldn't think it would take a private lender (which is much higher priced) than a typical mortgage broker's rates.Is there a reason you think you need a private lender?  

Quote from @Patrick Druryck Drury: @Srikanth Kumar200-250k is a reasonable price range in Cleveland for something that cashflows. in terms of areasI would recommend being in areas on the West Side of Cleveland like West Blvd, Cudell, Old Brooklyn, Clark Fulton, Edgewater, Jefferson, and Brooklyn Centre.

BUT, let’s say for personal reasons you want to “stretch” for faster wealth accumulation.  

I had a client who kept waiting for a better rate, only to see it jump 0.5% overnight costing him thousands.

Purchase price: $15,000 Cash invested: $25,000 Sub to deal - paid the seller and wholesaler $15,000 + $7500 closing costs to assume $84,000 mortgage with a monthly PITI of $575.

One question that you may not want to post here for legal reasons, is how much are you paying your PMC?