The main reason Pendolino are cheaper is its an old design thats already paid off its development costs but even the new ones are fairly expensive to insure because of their lack of age. But this is an argument thats simply a race to the bottom, an IC125 is cheaper than a Pendolino, a Sprinter is cheaper than an IC125, a pacer is cheaper than a Sprinter.
You want Wi-Fi, lots of electrical sockets, air conditioning, more energy efficency? you want a modern design youve got to pay for it.
R.e. above, I believe Hitachi has actually spent in the region of £20-30m on design work already, while their initial submission was an outline specification the fine negotiations that have taken place over the last couple of years have been with a detailed design tackling the normal problems you find when you move from theoretical specification to physical blueprints (like the fact the transformer was under rated for the power it needed to draw, and that certain components were over weight). That doesnt include the amount the Dft has spent on lawyers, accountants and consultants to evaluate reliability, practicality, running costs and feature inclusion (reportedly in the teens)