Hi Tim, I know lots of things, not just toys are more expensive in the UK.
Really, it shouldn't be too bad, espcially with the GBP being so strong of late but unfortunately many retailers are very naughty and instead of working out the different currencies properly, they just exchange the dollar sign or the euro sign for a pound sign.
To give an example, I recently bought a music book for £14.95. When I checked the price printed on the book, it was $14.95. Translated back, this means the book actually cost me almost $30. Okay, maybe a slight price increase would be acceptable to cover shipping costs etc. but to almost double the price is wrong.
Smurfs are a bit more tricky. If you look at ebay, prices seem to be pretty low at the moment, probably down to just the sheer amount being sold but as we don't have them stocked in retail outlets, it is hard to show whether the prices would be more than say in Belgium.