I just heard from my mom, and she said my aunt and uncle got a room at the Newbury Guest House for $179/night. This is a great little B&B, right downtown. Seriously, it's a block from my house. And between the breakfast part of B&B, the non-requirement of cabs, etc., it'll likely be a better deal than you'll find elsewhere.
I'd make reservations via the phone, because online, it says they require 3-night stays. They don't--I spoke with the reservation agent.
Also, I found The Chandler Inn Hotel. I don't know why with the "Inn Hotel" thing, but it looks halfway decent, is less than $150/night, and is within walking distance of the Jurys and downtown. In fact, it looks to be about 3 blocks from the Jurys, on the edge of the South End and Theater District. Found that on Priceline... Search under Boston (city) for location.
I'm a little stunned, honestly... It's not the Ritz, but... www.chandlerinn.com 617-482-3450
ALSO!!!! One of our guests did a little searching and found The Midtown Hotel. www.midtownhotel.com. Looks reasonable, is in a good neighborhood, within about 9 blocks of the Jurys, and nice! Look at all these places I didn't even find!
Hope this helps! And I apologize for the disjointedness of this all--I keep adding when I learn something new. Perhaps one of these days, I'll pull it all together and be really organized. But perhaps not. :)