Some of them I actually used in my Graduate degree classes.http://www.biggerpockets.com/renewsblog/2009/01/01/6-reads-investors/

A plain-Jane, 20 year old property that is cute and nice but nothing spectacular will get you the lower end of those numbers, whereas a brand new 4 bed with a pool will get you on the higher end.The net will be dependent on you and can vary from person to person so that’s hard to project based on loan type, management style, etc.

Scott uses 3% of the sale price for an extra bedroom but I'm sure this varies from market to market. 

The people above have tons of other options, with varying risk factors.Literally while typing this post, my realtor just called and we have an offer of $87,500 on one of our 2 acre $100,000 listed lots. 

I don't think things are as bad as they were, but I'm not going to take a chance when I hear of tourists getting pulled off the tourist bus and robbed at gunpoint.Other countries in Central America have varying levels of safety and political stability. 

If you can house hack you will have the best options, if you cannot live in the home then the options general are not very diverse and will vary based on if it's a 1-unit or multi-unit property.  

Remember, our retirement accounts charts should look like a hockey stick, not a straight 45 degree angle... that money doubles itself every 5-8 years... doesn't mean much when you have $10,000 in, but when you have hundred of thousand in it starts taking off.

This varies so much!

It will vary depending on your individual situation. 

@Josh Horst That's awesome you graduated from CU Boulder, that's where I graduated as well with a degree in Finance.