The £15 fee is a standard offline fee, which is usually undercut by a couple of quid by most (but not all) travel agencies.

There is no separate fee for having a paper ticket. The £25 fee you have been charged must be for the setting up of a PTA (Pre-paid Ticket Advice). This is essentially where a ticket is issued at a ticket desk or office in a different country to where payment was made - you paid for your ticket in the UK, and the ticket will be issued in Italy. I am guessing that travel is at fairly short notice which is why a PTA has been setup, rather than mailing a ticket to the creditcard billing address?

You might have saved a few pounds by booking at Expedia, but these charges are not included in the Price Promise thingy. However, I will make a blanket, sweeping statement and say that intenet travel agencies are ATROCIOUS and DIABOLICAL when it comes to PTA's. They are frequently setup as regular bookings and the ticket desk will have no record of a PTA (and, therefore, no ticket) as the internet travel agencies are just too automated to handle this kind of process.

I would only ever trust a human being travel agency or the airline when it comes to PTA's (and both have their own fair share of horror stories on this issue). A travel agency would, almost certainly, have their own fee for assisting with the setup of a PTA in addition to their own booking fee. Overall it may very well come in less than by booking direct, but the saving would be less than £80.

I suspect that ultimately you don't have a leg to stand on when it comes to recouping any excess you feel that you've paid - but I would not use the Expedia quote as my measuring stick for this.