All the people I know who are generating rental income in DC/Montgomery/Howard area bought a long time ago.

The initial investment was low, and is generating almost 30% ROI annually.  

Another thing to consider (if you're looking at the 4% interest paid back to the 401k vs the x% return a 401k investment could generate) is the return you would get from the investment property and whether you could acquire the property without the loan.

While I understand it helps to have a set goal, the reason I'm asking in general without a set goal is because I'm trying to see what creative ways are out there to generate maximum return. 

i have an opprotunity to by 6 houses all are rented and generating $3525 per month.  

I recently made an offer on a property...It was a 10 unit apt building generating 3k a month...He was asking 180k.  

Cars all accomplish the same thing....take you to your destination, whether it costs $100 or $200K.My focus is on Real Estate as I see where my money goes and it generates cash flow!

We've talked about investing in a small house or apartment and potentially renting it out to generate some cash flow (easy to find tenants as a university student, I'm very comfortable with roommates). 

Then, he also told me I don't need to document my tenant screening criteria and that I should rent to males instead of females because "in his generation" females were tougher on properties. 

followed by some random phone number.