I definitely think you should keep your eye on Costco. I went to SWA for my rental beginning Jan. 25 and returning on Feb. 8. The least expensive car there is $400 with Payless and my Costco is $343 with Budget. Budget with SWA is $423. The air miles earned won't beat my 3% cash.
Obviously our rental locations could make the difference, but I just don't want anyone to discourage people from checking Costco.
These posts also illustrate to me why I don't use a TA for everything I do. No one is going to do better than I can to get me the best deal.
Of course,
DCL is not a big deal because the cruise fare is the cruise fare. One agent may give a client different perks, so go with what you like, especially if you are new to cruising, and new to DCL and have a lot of questions.
You definitely have a very unique situation. I don't have a small TA in my area that is going to be cruising on Disney and I would think that doesn't happen very often.
I will point out, that DCL pricing more easily facilitates your situation. They don't allow any discounts on their cruise fares. If you were doing other types of travel, or even other cruise lines, you may be happy with what your agent finds for you, but it might not be the best deal, and that may be fine with you. I actually enjoy researching my travel and I have been able to save thousands over what I've been quoted by TAs.