I agree about airlien websites charging more for the flights, than on their main page.
This week I booked flights with Ryanair from DTVA to Dublin.
When you open up the website is says 2 million FREE seats.
When I went through the booking process (for 2 pax), with selecting online check in, hand luggage only, no priority boarding, and no insurance, and paying with a friends Visa Electron card the fare really did jump up.
Instead of being FREE, I ended up paying £0.04 (yes, 4 pence). TOTAL COST.
I was horrified at this increase