We used to get round the "preferred supplier" blockage in development by using a tame preferred supplier who were quite happy to quote for anything. They just added 25% handling charge to whatever they paid for the parts! Our purchasing dept may or may not have twigged what was going on (being a part of a multinational the actual purchasing was done in India so quite possibly not....)? We got some very esoteric electronic components for some development jobs from Newbury Welding
