A direct booking site still has to process a credit card payment.

.** (Isn't that what making monthly payments on seller buyback is?)

Think of it as a portfolio mortgage and a first mortgage combined in one step to give enough security to have a low/no down payment for the new property. 

The issue is, I fell for his traps and gave him 75% of the payment (around 35k) because he kept saying he needed it to get done soon and I did not want to extend my lease too much because it was very expensive to do so.

Im advising client who want to buy vacation rentals to have a padded bank account because the income stream is not as reliable as it once was. 

In some areas, you will never cash flow (well if you pay cash or do a massive down payment).

I figure the interest only payments for land loan would be roughly $2,100/mo. (800K @ 8% for 3mo).

I'm looking into a few different options now: HELOC on other investment properties (though I'm finding rates are 11%-13%), a business loan on another business I own, and negotiating with vendors to take deferred payments. 

Fannie/Freddie then require you show leases and then use 75% of those leases to offset the mortgage payment. 

It was a pain to get good quotes and available people to build out spec homes and I needed a reliable/credible GC to qualify for the loans I considered anyway.2.