Hmm, I've found that generally the prices are the same but in pounds. So if I paid $3 for a bottle of shampoo in the US, it will probably be about £3 here (for the good stuff). Sometimes Sainsburys or Tescos have a "buy-one-get-one" offer but generally I mostly find that on just shampoo for some odd reason. Everything is more expensive in the UK, that's a given really. I think a good rule of thumb though, just to generalise, is just to slap a £ sign on the prices in the US and that will probably be about what you'll pay in the UK.