I can't count how many times I met with a seller and said my commission is X% (and I'll pay the buyer's agent out of that), and they replied that so-and-so says they only charge Y%. 

Count your no's and eventually you'll get a yes

I think the answer to this question really depends on a few factors such as your current unit count, location of your properties, long term goals, and how much of your income is based off of your units. 

You will have the odd desperate seller like an American who took a mortgage on his US home to buy a property in the Dominican Republic and was counting on the rental income in the Dominican Republic to pay off his mortgage.

Remember, the seller is counting on this to close as well. 

With a $500k investment you could probably easily grow to a $1.65M, 6 units portfolio, with cash flow in excess of $2,500/mo, all while reducing your structure count from 6 to 2.

A primary residence does not count for 1031 exchange purposes, so you would need to reinvest your capital gains from the rental portion of the 2-family into another property or DST in order to avoid paying taxes. 

This could be good if you plan to raise rents quickly, but it could also be risky if you’re counting on steady income to cover expenses.

As far as why I was considering an LLC - it seems like there's two camps, those who think it's a necessity for legal protection, especially as you grow in unit count, and those who think it's mainly a waste of time and money.

And ideally sell it 4 years later.If I can more or less count on the renting of additional bedrooms to cover the running costs of the house, I'm really only looking at taking a hit on the buying/selling costs - which SHOULD be lower than what it would cost to house him in dorms for 4 years.I feel like this is pretty obvious and easy (not trying to make significant money here, just thinking I could save $10-$20k on housing costs over 4 years).