I would not exactly call it "rigged", as displaying all the CO and NW fares would make it display a huge number of pages. It often shows some "Web Only" fares not available via telephone though (but not many).

I do as you did, check Orbitz, Travelocity etc for your best fares and routing, and then call CO to book it. Itsa faster overall too unless you have only one phone line or no high speed connection.

Flying CO outta PHL is really weird as it shows mostly Amtrak "flights" connecting in EWR at outrageous fares for the train part. It is far cheaper to book it separately with Amtrak.

MisterNice