Unlike in past years, it's remarkably easy to do the work of ExCon's hypothetical B&M agent. Granted, you're the one looking up travel options between Salem, MA and Salem, OR, but you have at your disposal the internet with several air-oriented travel websites, plus the Amtrak, Greyhound, and other bus company sites. And, nearly everyone has an all-in-one payment card provided by Visa, Mastercard or American Express.
That said, I'm surprised none of the major travel sites, or a third party like Google, has taken the next step: full comparison of ALL travel modes between point A and point B. I'm picturing a site that, if someone did want to travel from Salem to Salem, would give them the price breakdown of car rental + gas, Amtrak, Greyhound, other bus, public transportation, and least expensive airfare. After that, it would give the options of booking the trip by shortest time, least cost, best time-money value, or customized as the buyer prefers. Then, the site would be able to order all of the necessary tickets through the actual transportation providers, and assemble an itinerary.
As an example, it could order an MBCR pass from Salem to BON, thence the T to KBOS, airfare from KBOS to KMDW on a discount carrier, CTA fare from KMDW through downtown to KORD, airfare on a legacy carrier from KORD to KSEA, fare on Sound Transit from KSEA to International/Chinatown Station, and finally a ticket aboard an Amtrak Cascades Service train to SLM. Or, maybe it would book a SuperShuttle from Salem to BOS, a Megabus ticket from BOS to Secaucus, NJT fare to KEWR, then book a nonstop KEWR-KPDX flight and arrange for a car rental at KPDX for the drive to Salem. Such a site obviously couldn't guarantee connections, but if it could re-book a customer mid-trip without penalty (say, if Amtrak was having wire problems and held up NJT), that would be almost as good.
It sounds like a horrific amount of information for one company, but in reality it isn't so much. The most difficult travel option, the airlines, already book most of their travel through third-party sites like Expedia and Travelocity, and I'd expect a site like this to piggyback off their existing efforts as does the site Kayak. Likewise for Amtrak, Megabus and Greyhound, which all offer online booking on their websites. Commuter agencies have a large number of routes, but a fixed set of prices and a fixed schedule - that's relatively simple to feed into the equation. Finally, non-scheduled providers like livery services and car rental companies have no set rate, but would probably be willing to negotiate below-retail prices in exchange for guaranteed business.