You need to change the selection to say Emerald Reserve rather than Counter Service. Just click inside that field and then pick Emerald Reserve. That just means you can go to the garage and pick up your van from the van area and go right to the check out booth, without going to the counter.
What I generally do (and I think many others do as well) is reserve what you need now and continue to check back periodically for better rates. If the rates are better make a new reservation and cancel the old one. I am one week out from my reservation and my price just went down $80. I'm so glad I checked back!
The best rates have been found by using the Priceless code (6600330 - available to everyone) and an Entertainment book coupon for $20 off. There is a web address where you can print a copy of the coupon, but I'm sorry, I don't have that link. If you search for National Entertainment Book coupon, you might find it. Or, maybe someone else knows it.