I was just checking rates on mohegan sun and I was pleasantly surprised to see some serious discounts when I logged into mymohegansun.com even with my very lowly rated players card.
Oct 31st-199 on mohegansun.com, $129 on mymohegansun.
Nov 22-219 on mohegansun.com, $129 on mymohegansun.com
Even some weekend nights give $20-30 bucks off (not worth it at $450, but hey its there and that's what counts right?)
Now mohegan does offer $50 off weekday nights with 30 days notice (changed from 14 days notice not too recently).
So my advice is to get logged into Mymohegansun to see what your discounts are. I'm sure i'm the lowest of the low (i've had a players card since 1999 but I only visit 5-6 times a year and usually gamble $150 a visit).