Rents can go up and down in price, but in my area at least, they seem to go mostly up. A good way to check on the going rates in your area is to check with Sec 8 to see how much they would subsidize for units such as yours (it will depend on # bedrooms, in part). That's not to say you want a Sec 8 tenant. Check craigslist, your local newspaper, etc. to see what others are charging for similar units.