Didn't the Nimrod AEW 3 suffer a similar fate, as there was no fixed price on the contract, so a lot of money was spent trying to compress down the software for it onto the hard drive in the system, where the simple expediency of increasing the size of the drive would have cured it? but of course BAe wouldn't be getting paid then.
Nimrod AEW was not a viable concept for many reasons - it was bought because the Government of the day could not afford to upset the British Unions and therefore could not buy the much preferred AWACS option at the time. The cost plus contract that was given also meant that the more the company got things wrong then the more money they made. In the end - "jobs for the boys" cost the Country nearly £1Bn in 1980s prices. (Jeremy please note).
On a different subject - if you buy "off the shelf" then you have to ensure that the build standard of the components used is up to scratch and that they will be available throughout the lifetime of the product. If you replace kit using COTS then you change the drawing for each individual aircraft and you may end up with a mixed fleet and each aircraft different - very complicated for certification and the safety case when you update kit.