rh200 has it spot-on! Well said Sir.
Hempy - those aircraft cost way more than the £90M you quote because they are Low-Rate Initial Production (LRIP) airframes. When Full-Rate Production (FRP) is in full swing you might see them come in at the price you quote (from where btw?!), or it could be higher (or lower, but I doubt it). I think the cost is irrelevant in many ways to this argument, unless of course you can quote an ac cost that would be acceptable in similar circumstances?
If it comes to the UK, great. If it doesn't, the more mature visitors to this forum will understand why.