OK, so let's say you loose your job, and have money worries, should you go out and purchase every high priced brand name alternative for a perfectly good, possibly even better generic product, at twice the cost. A coast to coast cycle is just a marketing idea where one eliminates about 99.99999% of the route ideas in order to travel from a well promoted departure point to a well promoted destination, while traveling along the same route as tens of thousands of other people while consuming routes, product lists etc... developed by other people. That may or may not be the best option right at this point.
If I was choosing such a route, I wonder whether a wilderness route like the Great Divide trail, with many more options for free camping would be cheaper and possibly more rewarding (negative of getting to and from that route might be costly). Other options would be to do a long hike like the Appalacian trail or Pacific Crest. Less gear, and lots of wild camping alternatives. Less crowds and dives to spend money I am guessing.
I like the idea of selling you truck in SF as a precursor. I might consider ebay since those deals normally involve pre-payment, where the local lists are more based on tire kicking prior to handing over the money. So you could find you don't really have a deal when you get out there.