Last November I rented a car from National for 10 days and paid $203.00 including everything for an Intermediate. This was with EI discount but no coupons. I would say your rate is a good one that will most likely be hard to beat.
We have a reservation with National using the Emerald Club for 10 days Nov 20 - Dec 9, Full size total including everything (but never insurance) $179.
The base rate was $124 additional days $20 and I used the Disney Club contract for discount and a $20 off coupon.
Thanks for the replies so far. I used the DC contract ID plus an Entertainment coupon for my rate and the system accepted it. The base weekly rate was $124 for the Intermediate car.