The Big Arse is a rare piece, I think there is only 1 other around, th emould changed hands a while ago, but I've forgotten what happened to it.
As for price, I think it's still a bargain, the basic frame with standard fibreglass parts came in at over £2k in it's day. You have all the other bits, suspension etc, would be nice if a V5C was in there as well, so you're looking that Malcolm has around £3k invested in it.
Last one I bought as a unfinished project cot me £1200, it wasn't in particular good shape, although most of t was there, I now have a reasonable buggy on the road for £2k. If you buy this for £500 even with the IVA costs you could have a nice buggy on the road for the same £2k.
I know if I had the space, you wouldn't be able to buy it, as it would be here with me know, but then again I'm biased.
Alan...