There's one of these vases in blue that's been pottering about in a second-hand shop in Nottingham for about 9 months at £6.50. It looks sad and lonely, so I'll probably eventually buy it.

But here's one on eBay which recently finished at a little above £10:
Auction Link - but I would say that's an above-average price. When I was looking online to see if it would be worth buying the Nottingham one to sell on at a profit, they were mostly ending at £5. Either the market is on the rise again, or you have just landed unlucky in your searches!