We too need Visas to visit the US.
Airfare from Mexico is expensive too, but not as expensive as it is for some of you traveling from the other side of the world. Direct flight tickets cost about $ 700, and the trip duration is about 3 hrs. Tickets with a stop in Houston, Atlanta or Miami can cost as little as $ 450.
We always rent a car when we travel to the US (except for next trip since DH won´t be coming with us) and we decline the basic coverage since the American Express card that we use to pay for the rental has very good primary coverage, but we always get the additional insurance.
If you are planning on using ME, and your first port of entry to the US is Orlando, you will have to go through inmigration (be aware of the lines, last september we were 45 min in line), then get your luggage to go through customs, and then you will have to put your luggage in a sort of electric band in a tunnel that will take it to the main building while you board the train.
Just after customs, and before putting your luggage in the electric band, attach de yellow tags to your bags, and then you can skip the central baggage claim and proceed directly to the ME counter. We have done this twice and have never had any trouble.
If your first port of entry to the US is another airport, you will go through inmigration and customs there, so after going through customs you can attach the yellow tags before checking your bags again and then when you arrive in Orlando you can proceed directly to the ME counter.
HTH
Julie