Are the units vintage quality with in-place rents $500/mo below current market?  

With comps ranging from $875K-$1M and your estimated build cost at $550K, the after-completion value gives you a significant equity cushion, making this project highly attractive to lenders.If you plan to hold and rent the property, you could refinance into a DSCR loan after construction, which bases lending on rental income rather than personal income.

High taxes.

- Highly recommend REQUIRING tenants to get Renters Insurance and adding you, as the landlord, as additionally insured.

If you think that the forums and the books have the same information and the same quality, do you read books at all?

And I will stay in my condo until I can afford to buy a bigger place.However, with high interest rates, I’m reconsidering.

Real estate agents are not highly regulated in Costa Rica as opposed to North America.  

Highly recommend (I require) collecting first month's rent prior to handing over keys.

Contractors, unless you have a working relationship with them, normally do not want you bouncing ideas off them.Understand what their hourly rate is, have a discussion with them that you are okay with paying them an hourly rate if they walk the property with you and provide you a scope of work along with an explanation of what you can/can't get away with in regards to improvements.ask them if you go with them, if they can credit you the amount that you paid.Once you develop a working relationship with a few contractors, you can bounce ideas off them and expect quality responses.I do not invest in New York.Best of luck. 

Rental arbitrage isn’t common in my area ( high point North Carolina) but I was planning on starting in another state.