yelnaD and John are describing a different, but important aspect of real estate investing. Buying and operating rental real estate at market prices is profitible, in general. Finding deals is another realm, is a lot more work on the digging side, and is much more profitible. Unfortunatly I haven't found those yet.
So, yelnad's rents and prices are not market rates. I was wondering about single family market rates - and I believe from memory and cases I have seen that rent is between .6 and .7% of the purchase price per month (but I have no current data to back that up). Multi family (>5 units) tends to be around 1% of the purchase price per month (and I have lots of examples in Denver for that). This simply was to illustrate the difference between single and multi family for rentals for cash flow.
I'm sure it is possible to find deals. In fact my sister recently found a good one. Someday I may stumble on to one, but not because of extensive looking. My sister follows all the auction notices in her small town. She saw one for a house she had her eye on (for a home for our mom), and tried to go to the auction. It got postponed 3 times before it finally was held. One other person showed up, and stormed out when she bid it up to about 60% or 70% of value! She walked into a setup sweetheart deal, and got it for herself. So it can be done, but note that it took some legwork to track down the rescheduled auctions.