Travel Troubleshooter: Bought off-line, the airfare soared

Question: Is there a difference between the price you pay for an airline ticket online, compared with off-line? I recently tried to buy a ticket for my mother on Expedia. She wanted to visit my brother in North Carolina, who was on life support. I kept getting to the end of the process, and it would not let me complete the transaction. The online price for her round-trip ticket from Tucson, Ariz., to Fayetteville, N.C., was $490. I called Expedia’s customer-support number. A representative tried to “help” me by charging $1,123 for the identical ticket. I asked why there was such a huge price difference and was told that I must have been looking at the one-way fare. I reluctantly accepted this answer. The next day, I went back online to check prices, since my wife would also ne...