Looking to Purchase a Preconstruction? Strategy for Quicker Ownership.

I am currently looking to purchase a pre-construction unit in Mexico to add to my Airbnb portfolio. I was on the phone with my real estate agent discussing the finish date and payment plan for a unit that would be finished in late 2023. As we were talking an idea came to me that would help me pay down the outlay of cash for the unit soon after I get the keys to my unit. 

My payment plan was to put down 30% now to get it under contract and pay the remaining 70% upon closing. Generally speaking, the higher the downpayment the higher the discount. Instead of purchasing 1 unit for 15% lower than market average, I would get another unit under contract. When delivery is complete in 2023, I would have to find the funds to close on both properties. Once I have ownership of both units, I would put the 2nd unit on the market and use the proceeds of the sale to go towards the downpayment of the first unit. Although the market for a post-construction can be way more than 15% at the end of 2023 (mo bonus) or go below the value of what I paid (my loss), this is a strategy to consider when purchasing a reconstruction unit.

Let me know what you think of this strategy and what other options you think would work to get faster ownership of your vacation rental.