I have a room for 2 in a B&B two miles north of downtown.
Beats airport or further out.

Looking Glass Inn - Crimson Room
1319 North New Jersey Street
Indianapolis, IN 46202
$180 a night (Plus Tax)

I guess it's romantic, if you're into that sort of thing. Shoot me a thing ASAP.  [email protected]
It's probably the cheapest room you're going to find within 2 miles of the convention center.