One thought - what bank is going to allow a seller carry in the second position for 21% with the purchaser only having 4% into it?

However, you do make a good point of possible carrying the contract and making the interest and saving the money on the $ I would have put into the rehab.  

Instead, determine the local tax rate and use your purchase price to calculate the new property tax amount.Home Insurance: If you're using financing, your lender will require you to carry a basic fire insurance and liability policy.

The cost of installation will be dependant on numerous items such as:-how many will be installed, how much jacking needs to take place and at how many points, is it a basement or crawl space, will they be installed on concrete or will post pads have to be dug and poured, is it a one or two story house (how much load will each post have to carry), etc. 

Otherwise you do a lot of due diligence that is a sunk cost and if not paying all cash you will have carrying costs of the property taxes and mortgage payment until you can develop the land to get income coming in.You need that 6 months of time before purchasing.

Alternatively, you can get the seller to do a seller carry/seller finance for 10% and put down the 10% that would solve the 20% issue.

Lots of good folks out there earning peanuts on their savings.If I can get a seller carry at 6% on another little house to accept a $5k discount for an early pay-off (essentially bringing the return up to 8%), I will satisfy that one as well when my other place sells and potentially leverage it.  

I dont want to publicly shame the individuals....but after doing the math using the numbers they used on the TV show for purchases, sales and renovation costs, and estimating the carrying costs using typical hard money rates for the market where the property was....Im estimating the flip lost $13,000.

Nice job, good returns, low carrying costs.  

Find the retiring Mom and Pops who will carry a note and accept a cap rate that provides your target cash on cash return and you'll be fine.