hi teuchtar,
For those who are not in the Trade, take a look at the autotrader.co.uk website. It has a section for both cars and vans, you can select by age, model etc to narrow your search. Register (free) and you can search the whole country and get further search options. Fantastic site. Plug in the details of the van's you are being offered and take a look at the results. You'll need to check which ones are being sold privately, which are being sold by a garage and make up a variance of price range. Vehicles at a business will tend to go for a higher price - remember, reputable ones will have cleaned it, fixed any minor issues, maybe offer a warranty, had it inspected with a certificate, maybe paid for MOT and road tax etc etc plus of course adding their markup/profit. Good thing is you know (pretty much) what your getting and importantly do have recourse if something should go wrong.
Private vehicles are usually substantially cheaper - of course, it's then up to you to determine if the vehicle is good enough to go for. There are plenty of guides on the site for you to read and get to know what you may need to do if viewing/buying a privately listed car/van
Seeing as your company is offering an 'in house' auction, it's a little 'unfair' as it can be easily 'rigged' and most probably has - I don't mean in a bad way, but what they've doen or at least I think they'd have done is taken a look at the 'Trade' listing for values, it's known as the GAP book or Glass's guide (If i remember correctly) Trade prices are substanitally lower and I'd thought the company would have set a reserve of somewhere between that and the 'private' sale price of the van - this is so they dont lose tooo much value out of the vehicles, and saves them having to go to one of the big vehicle auction sites around the country.
Finally, if you do feel brave after researching, the cheapest place in the country to get a car or van is at one of the Auction houses specialising in cars - largest one is ADT auctions that know of and thats in Blackbushe near Basingstoke. I think you're from Scotland? I remember going to auctions up there and being astounded at how much cheaper similar vehicles were there compared to here. You can bag some bargains -I bought a Transit a couple of years ago, during a company fleet disposal and got it for around 1500 less than the 'book value' - it's nerve wracking for sure - the risk is it might be a complete dog, but I only bidded on the warranted and company auction items which do have some recourse!
Start off with the autotrader website and read all the articles and then compare listings so you have an 'idea' of the kinda prices the same models go for and maybe then bid for the ones being offered !
Hope this helps!
DtM! West London & Slough UK!