I worked at ITA software for a few years, in the team that wrote the software that searches for airfares. The prices of seats and their restrictions are publis

I worked at ITA software for a few years, in the team that wrote the software that searches for airfares. The prices of seats and their restrictions are published, and the data format predates the web (by a large margin). There's no field for "browser type." Each seat has about a dozen prices, and the only other way the user sees a price change is by turning a given price on or off. But the protocol that asks whether a given seat is available doesn't have a "browser type" field either. When you go to an airline's web site, they could presumably use whatever info they want. But if they used the browser while travel agents didn't, they'd either be presenting a lower price than you could get through the agent, or a higher one. It seems unlikely they'd do that, but I suppose it's possible.