This place seems to have a wide selection and some more reasonable prices:
http://www.discountramps.com/wheelchair_carriers.htm
I just googled 'hauling power chair' and got quite a few promising leads. You might need to winnow down the wording to get it just right. Then if money is an issue (as if it isn't always), try for a used model of exactly what you want.
ess
I am sorry this is a bad problem. Do you want to know where to get a carrier or how to get help paying for it? Yes Medicare expects you to stay home.
We have many in our community who can't afford lifts, vans, or power chairs and are stuck at home. Our chapter of the NMSS can't meet the need. It is to great so they help no one on that count.
I have a friend who sells medical equipment locally and he simply can't stay in business on what medicare is willing to pay so he has to turn people down. They want to pay him less than what he gets the equipment from his distributors for. It breaks his heart. I never understood until he explained it. The government wants to pay thousands below wholesale.
The United Spinal Association Magazine has ads for equipment. People with MS can join for free. You can get discounts on all kinds of things like hotels as a member. They also have good articles on MS even for those not in a wheelchair.
Craigslist is a place to find used medical equipment. A friend of mine bought a used van then got one of the mechanical wheelchair ramps on Craigslist. It was cheaper then the Van and ramp together new. Or you can google car wheel chair carriers. If you do not feel safe take someone with you, meet the person in a public place for Craigslist and use money so they do not get personal information from a check.
Alex