REI is a get rich slow game

Of course, the most important thing to look for is a good location. You want to be in the path of development and gentrification, which will increase the odds of appreciation.

Count on appreciation to peg inflation-2 to 3% per year. It's a slow game. Anything above that is icing on the cake. 

And, very important, make sure you cash flow. The rents must be able to support all the expenses and give you a decent return on the money you've invested. Think of it like putting your money in a bank, but with much higher interest because you'll be working for that money. It's not completely passive.

Cash flowing a few hundred to a few thousand dollars a month won't make you rich at all. It's just a margin of safety (to make sure you can pay all the bills and be able to keep the house even in a down market) and gives you some extra spending money.

If you get those 2 things right, you just may find REI to be a great, lucrative game to play.

And, if you're lucky/educated enough to hit the right market, at just the right time, it can pay off huge.

At a minimum, you should be able to get rich slowly/ultimately. And, you don't need to be rich to get started. But, you should at least have a decent job and a good amount of savings to fall back on.