One of the biggest hurdles right now is getting a deal.

Your biggest expense will be adding a sprinkler system since this type of zoned property has to have one.

I'm in Canada where tuition is different (not as expensive as the US), but the biggest expense I see is what students pay for housing and food, not their tuition (US is likely different).Real estate investing is not passive and not something you can live off.

If  you are in the 20% range, you are better off going to the casino and putting all of your money on black and seeing what happnes.Since you are out of the area properly calculating cash on cash returns can be difficult because you have variable expenses to calculate. 

One theory is that the investors see population increasing in these areas and are willing to deal with the ridiculous local laws This actually isn’t even necessary true, the placest with the biggest per capita housing production or “investment” is in the sunbelt, the expensive cities produce a shockingly low amount of housing, obviously zoning laws play a huge role in that as well, but even when you looking up institutional investment in existing properties it’s mostly in the sunbelt, most people who own big buildings in hcol areas just bought them decades ago when they were much cheaper, even D.C. has has like a 4-5 fold increase in value in some areas in the last 15 or so years.

The biggest thing that will limit your ability to buy multiple houses a year is that thing between your ears.

My biggest concern is that some of the houses right across are multi-family duplexes.

The biggest challenge is all realtor appraiser are an in the moment snapshot. 

Your lender can be one of the biggest assets on your team.

Think of the bank as your biggest partner.