I made up a spreadsheet before my Dec trip last year with regular rates and what the expected BB rate would be based on the brochure and what others reported for availability/rates. I called while there and got the 30% off our upcoming April trip, but then the AP and SPECIAL OFFERS came out and I was able to book an even better deal, but didn't call to cancel the BB offer until I had finalized the AP rate.
I'm planning to do it again the same way for the December trip I also am planning this year.