Some investors buy land in cash or with short-term financing, then refinance it later when they’re ready to build.Lastly, don’t underestimate the power of networking.

Short term.  

Short 1.5 minute video walk through of all of the rooms, bathrooms, common areas, etc. 

I indeed have learned a ton from them in a very short time. 

This plays into the affordability issues for tenants by allowing them to live in nicer neighborhoods for less money, yet I get monthly revenue comparable to short-term rentals.

If in the rare chance they do allow short term rentals in the HOA rules/regulations and association documents, don't be surprised if they change that ruling after you buy. 

The area had appreciated substantially in a short amount of time.

Was thinking it could be good for a short term rental or maybe just renting out a single family.

You will be competing with people who have 'boots on the ground' and can visit any property owner with short notice.While wholesaling from afar is possible, it is recommended to begin closer to home.

I agree with @Jonathan Greene that the question is vague, so my advice will have to be as well.The short answer: MTRs are real estate, so just like all real estate, any place that can long-term-rent cash flow with increasing jobs/population can be a suitable site to purchase.