D*Con is not for the faint of heart lol. Most of the main hotels will have sold out by now because if you're not booking a year ahead of time, you'll miss out. Much like a celebration, this con takes a lot of lead time to organize. There are a few cheaper hotels closer to the main locations, a Best Western and Days Inn, but I'm not sure they'll have rooms left.
D*Con is also different because it is not held in a convention or conference space. It's held inside the sprawling host hotels. It never stops. If you have a cheaper room that is further from the host hotels you can miss out on much of the insane night life that has made D*Con popular. Also, parking is a beast if you decide to commute in from further away and public transportation in Atlanta is lackluster and shuts down rather early. Plenty of people do it, but its not the ideal.
However, if you're more interested in the normal daytime con activities you might be fine. But for me personally its worth the investment to be as close as possible to the action. To defray these costs, we usually throw 6 or 7 people to a room. If you are only two people, that is an understandable issue.