I have been using all of these and the rate for National is over 1000$ for my trip (9/24 - 10/2, 5pm pick up and drop off) and Alamo is 777$....if you can get something to show up for the 300$ rate without costco, I am interested!!!
I just rechecked the costco rate and its 600$...so less than the others, but far from last years prices....
I am willing to pay the 300$ for a mini-van, but I will be very unhappy if I hear that others ended up picking them up for free in a full size aisle on Monday!!