Some big buildings do their own marketing, so they don't have realtor fees. But, their rent tends to be more expensive. Just do the arithmetic for the places you're looking at: saving one month's rent by not going through realtor is equal to a 1/12th discount over one year. For example, one year in a $2600/month place with no realtor fee will cost you just as much as one year in a $2400/month place with a realtor. $2600*12 = $2400*13 = $31,200.