Rent tends to increase exponentially at around 2-3% per year. The difference is that generally homes are a store of money in relation to inflation and rent is not. On a fixed 30-year mortgage, that $800/month will only fluctuate with the cost of utilities and taxes.
The obvious tradeoff is that it's easier for a renter to become mobile to follow jobs and presumably increased pay, but really it's a lifestyle choice.
Here, the NY Times made this all into a graphic awhile back.
http://www.nytimes.com/interactive/business/buy-rent-calcula...
1) Landlords often delay rent increases to keep good tenants. Of the apartments I've rented over the last 15 years, this has been the case.
2) Even hot markets have down periods in terms of rents. SF saw decreasing rents in 2009.
I'll just say that I ended up renting when all my friends were telling me I was stupid not to buy. Three years later I walked away from my rental after paying $30K total in rent, while my friends ended up losing more than $30K when the price of houses dropped (only 10%). That doesn't even include the mortgage payments they made as well. All in all, they paid twice what I did for a place to live.
Also, home owners often forget to include the cost of their down payment. If you put $100K down and your house appreciate 2% per year (which is pretty decent) you're out the extra 3-4% the renter made by keeping that money invested in the market.
I think we can agree that owning a house sometimes is a good thing, but it certainly isn't the best financial move for everyone.