You can revalidate your FAA IR in an approved flight training device, much cheaper therefore as have heard of £400 for Seneca I, (although I wouldnt recommend relying on this totally- you want to get in an aircraft at some point after all!) and as has already been pointed out all you need is a CFI not an examiner.
The other option these days which is becoming more attractive is to follow the FAA route and then convert to the JAA. A friend has recently done this and reckons he has saved a good few thousands of pounds- not to mention he now holds two licences rather than one.
I know of one flight school that has just started a Zero-ATPL including 250hrs RHS turbine for $42k (£28k), great if the currently weight restrictioins were not in place although they are working on a similar program which includes 250Hrs RHS of a 737 based in Europe. No prices for this one yet though.