Have you considered staying a bit more upscale Marriott locations and then using Bonus Bucks or Premium Pounds as a method of payment? They reduce my nightly rate considerably and I absolutely hate paying more than $100 per night for my lodging expenses that do come from my own pocket.

Alternatively you could try if you could get some good deals on Priceline for that particular city.

I have received the points on Marriott program for most of my Priceline Marriott stays that I did last year when I made sure that my MR number was on the folio when I checked out.