Stickmonkeytamer, you've been speaking to the wrong stackers.
The guys at my place couldn't be more helpful. Ask and it shall be done! (And it's rarely charged).
I should add that I know that the MOD Police monitor ebay all the time looking for dishonest stackers, (something in QRs I believe makes it a serious offence to mess about with "Her Majesy's stores"). I hear that they've not convicted more than 2 or 3 civvies in the last 5 years. Most of your ebay stuff is, I believe, from "Walts" to coin a phrase from our Army cousins. Mainly surplus shops and individuals that have bought from other individuals within the forces. (And generally those individuals are not from within the supply branch).