How do you guys book a multi airline fare seen on ITA Software? Do you book it on Priceline/Expedia, or do you use a travel-agent? What is the fee that a travel agent asks? I have now a ticket with 6 legs on 4 airlines, would like to know the best way to book it.

PS does anyone still use a Travel agent these days? what is the average fee that they are asking?

Thank you