I thought I'd seen some piccies of yours at some point, are they really worth £1K these days ?
Who knows...?? The 'value' on ebay for this and a whole heap of stuff is really down to what someone is prepared to pay for it. We've discussed this numerous times on the forum about things like Woodlore knives etc.. That said TBH they're not that common and things like mint SAS/PARA issue bergens sell for a lot of cash (for what they are) as do things like 42 pattern windproofs, Denison smocks etc on ebay.
The VC did sell for a lot of cash when new back in the 80's we discussed this as Rabbitsmacker says over on the 'Canvas Crusader' thread. I guess if you were really after one for reenacting or something you might pay a good whack... 1K seems to be a bit excessive IMHO. But the auction is actually saying 1K BIN open to offers.
All that said it's actually a very useable rucksack well made and plenty big enough for most mortals.