Cagey
Now I know what production car the disks were originally fitted too, sourcing them is easy, I dare say the £25 I paid at the local motorfactors for a pair maybe on the high side, however the point about using the motorfactors was to ensure I bought the correct disks, at a sensible price, the guy at motorfactors measured the old disk and matched it to the correct new part using the measurements and sizes in his parts catalogue. Suppliers such as CC, Redline, etc want to sell you the part at a vastly inflated price, keeping you in the dark as to its humble [and cheap] origins.
The same is true for updates, what clutch or starter motor do you use when swapping a X flow engine for a zetec? Raceline Dunnell etc will sell you one with the part number ground off !! When the reality is you need a bog standard SIerra DOHC plate or starter motor - sad I know, so you work it out.
Perhaps it maybe a good Idea to have a list on this site for 7 parts which were sourced from production cars, so us as owners could buy the standard parts from any motorfactors, and save shedfuls of cash