The LS is expensive in this country, but it is a fully loaded long wheelbase hybrid, which they don't sell in the US. The US LS also has to be specified with options to bring it up to UK spec, such as the $7k luxury pack, $16k seating package and the $2k adaptive suspension package. Also remember that the UK LS has £16k of VAT included in the price.
The GS 450h is expensive as the lower grades have been taken away, only the 300h gets those.
The CT is priced reasonably well. The Auris used to be much cheaper and better spec'd but over the last couple of years the price has crept up to be comparable with the CT. The Auris is still slightly better value, especially as it has a better 5 year warranty.