I recommend the Tally Ho-Tel at the Hamburg exit on I90 (Camp Road). It is ~4 miles from the stadium and really reasonable.
I originally had a reservation at the Holiday Inn on Camp Road for $109 and cancelled after calling the Tally Ho-Tel and lining one up for $59.
It doesn't look like much from the outside (typical townie motel), but the room was very clean, it had a table w/ 2 chairs, and even a small couch. I'll be staying there for the rest of my trips to WNY.
Call them at: 716-648-2000