Hmmmm,
I'm a great fan of contracting for availability. However, let's not confuse the method of procurement with the product itself.
Is the product (or the capability, if you like), innately too compex and expensive for both our budget and our needs? We could use a CfA approach (or even CfC - Contracting for Capability) with virtually any aircraft out there (we already do it with legacy platforms such as Tornado). But the overall cost will be cheaper with a less expensive platform.
Thus I think the original question is still valid. We can either have lots of cheaper platforms, or fewer more expensive ones - have we been seduced too far down the high-tech route?