Hi again, James!
Yes, all but one of my Hoovers are 240v British machines.
The exception is a US Model 300, which I bought late last year - it cost me $10, plus $60 (or £30) to ship over. I've never run it, since I don't have a transformer, and it's in the process of being restored at the moment. The bag's not original, sadly, so I'm on the lookout for one of those! I'll post a pic of it once the polishing has been finished!
The most I've ever spent on a Hoover was £220 inc p&p, which I paid for my Model 425 with tools. I only paid that much because the toolkit is very rare, since it only fit that model. As it turned out, the machine itself was in quite bad condition, but luckily I was generously given another one by a fellow collector, and I managed to build a decent one out of the two.
Not counting cleaners I was given free of charge, the rest of the collection has varied in price - from £10 for my Model 700, £12 for my Model 800, to £100 which I paid for my Junior 370. Price and value often goes up and down, seemingly without logic - a lot of my nicest cleaners are the ones I've paid least for!