All good advise above ...not Much to add..prices can be dictated by colour combination and wheel choice, factory wheels are best to my mind and the strong blue, red,silver colours with light interiors are the way to go.....only downside of the Ivory leather is its shows it's age yet all the black leather cars I've ever seen all look like brand new inside .
Dark leather also mean dark headlining ...so can feel a little claustrophobic or snug , light interiors feel ariy and maybe stay a bit cooler on the legs in the summer
The UK has a negative thing about high mileage cars so you could get a bargain if you go over the 100k but make sure it has Lexus service history and make sure all the big jobs have been done ....timing belt, tyres, ball joints ,shock absorbers .