When I bought my N Scale turnouts they were $25 or $26 at Klein's, the cheapest I found. Hatton's had them for $17. I am going to assume that their HO Peco will be around the same price.
Just took a look at the Hatton's site and it appears they don't deal with HO something I wasn't aware of as I play with N Scale sorry. With that being said, try other UK stores. Peco is going to be much cheaper from the UK as it is made in the UK, so long as you can get decent shipping. As said, from Hatton's shipping was a flat $17. I can't say about other stores but would think it would be similar or the same.