What did you have supplemental income when you started?

I'll give you my generic advice I give to any beginner.

You probably want to be careful about advertising too unless its one of those generic "I buy homes for cash" signs on the telephone pole.

Short term: I'm trying to help my dad get enough supplemental income that he can quit his salaried job and focus full time on his farm land/hunting property business. 

Big is different for everyone of course, but for me I'm talking 1.5M-2M ARV, and I would use as much investor capital as possible for the purchase and rehab in exchange for a slice of equity to supplement their cash flow on the back end.

I understand this is very generic, but hopefully this helps. 

VRBO, however, does allow supplemental rental agreements.  

Purchase real estate properties to be used as buy and hold rental units as a way to supplement my retirement income".

By using primary home loans you can put only 5% down for the home, using the cashflow from the last home to either supplement that mortgage payment OR add to your savings for the next home.

Your questions is like " why should i get exited to buy a car" ... too generic ..Having said that ... its really doesnt matter where you buy/sell.. as long as you know the economic behavior of that location and price properties accordingly. ..Real estate is very local (down to Zip code level) ...