Took a bit of a risk on this one:

(Pumpkins for scale, it's a big box!)
I've been looking for this for a while but mostly found £60 examples that were guaranteed 100% complete. Found one for £28 described as "appears to be complete" from a business seller on eBay, put it on my watch list, the seller made an offer at £25, I countered with £18 and they accepted.
Now I've got all three of the big Designer vehicles - 4402, 4403 and now 4404 - which has released some good chemicals in my brain. I just hope any missing pieces are common ones and not any of the ones unique to this set.
Edit: after a very quick root around the box it looks like I've got most of the very visible ones that would be hard to replace, so that's cool, but we'll see about the rest!
Edit: 11 missing pieces in the end with a total value between £1 and £3 (depending on used or new), excluding shipping because I've put them in my mega list of missing pieces ready for when I have about £100 to spend. The pieces, except for the tyres which have gone a bit white I think from concrete dust, are in excellent condition for their age too, no broken clips, nicks, bite marks or scratches beyond some minor clouding - not bad at all for 22 years old.
Meanwhile, other listings like this exist:

With two screenshots of a ton of missing pieces. The cheapest on Bricklink in the UK is £50 too, so £18 was good going. Not AS good as getting 4402 for £6 with a similar number of missing pieces but still good!