I would look at private money lenders who can consider giving your a line of credit based on a multiple of the cash you have. 

And how much can I expect to spend on this process?

I would also highly advise to spend 30 minutes and do a rent survey yourself and find comparable units and see what they rent for and charge.

I just want to make sure we are dividing out the cash flow we can spend versus the cash flow we should save.

Unfortunately, we can’t do this for another 200 days due to FHA restrictions.Exploring AlternativesOne potential solution I’ve considered is working with a private lender.

If you're looking to transact faster than that, then your only option will be private Buyers.Another alternative, other than the ideas mentioned above, might be to sell part of the land into permanent conservation. 

We'll have two private beach clubs (most developments in Tulum have none) and amenities at least as good if not better amenities than any other development in town. the great thing is that being close to the beach fits my lifestyle and vacation style so my goals are congruent.

I know people who do STR in their house, but it's as private as possible.

No but if you paid for those items you could get copies of them and use them for a private lender who may be able to give you a loan.

Sure, you are going to be getting/saving the Realtor commision, but in order to do that, you need to spend the investment into the Real Estate supplies that get you there.Thanks, I am certainly aware of the MLS benefits and agree.