Fortunately, I found few GPIB cables in the dumpster long time ago, but at some point I might need more and then I will face the same problem karoru has.
So I wondered how DIY cable would perform. Connectors like 112-024-213R001 and then, either:
a) IDC flat cable, signal, ground, signal ground, similar to ATA100 setup, maybe some metal foil shield on everything - IDC/ATA was kind of designed for high speed parallel busses but maybe not very long ones,
b) a bunch of Ethernet cables - not ideal, GPIB is not differential twisted pair, but these cables are super cheap.
What do you guys think? How much one can expect from such crude DIY attempts?
In principle it won't be necessarily cheaper, as GPIB cables on the ebay US can be had cheaply, but as karoru said shipping and VAT change the game.