That'll cost a lot of money to do so.

At the end that benefits me as the builder/owner.Cost per sqft - I mentioned that this is a very unreliable number, because a sqft of bathroom will cost a lot more than a bedroom.

Your only cost as a REI is whatever cash comes out of your pocket. 

I will be hosting a mastermind retreat for experienced millionaire investors (100 or more REI deals) out of my properties in Costa Rica in April.

Of course, actual finish materials such as tile, countertops, etc. vary in ACTUAL  cost a great deal, so you need to know where your figures land within a range of costs if you do not fine tune each estimate.

However, being self-employed really increases that cost, as you are the employer covering it now.

Despite hearing all the rumors on how much of a headache it is being a landlord I went for it anyways.My model was to invest in a nice unit that cost a little more upfront to hopefully attract responsible tenants. 

@Alton Pettit people who want to live in Hawaii only say that because they have never been to Costa Rica.

My kids will be out of high school in a little over 4 years, and I may want to move to Costa Rica or something

Most are the same cost as when you're learning a system and running your own - and they can talk to you about the types of lists that might work for you.Lists are the least expensive part of your campaign.