Figure prices rise and fall.
I look at ebay and I see Time Crash selling for 200 pounds. No bids tho. Then there is one for 20+ pounds with bids and days to go. Then there is buy it now at 47 pounds.. It goes on. The B/W Doctors sell regularly at about 50 pounds a set. I got mine in the US for $40 each set. Then more than that again for postage owing to a miscommunication!!!
At the end of the day, if you want something and you don't have to think twice about the cost - then you buy it. I do not agree with those people trying to turn a fast buck by chatging a lot, and if possible, I will not entertain them.