You are right that I'm pedantic. The reason for that is because I don't like seeing things stated as fact that are incorrect. I don't mean to offend you by being like it but if you take it that way.... oh well
Anyway, I'm pretty sure all all Supras, regardless of UK Spec, JSpec, US spec, were built/assembled/whatever you want to call it, in Japan.
The parts aren't obviously cheaper though. 99% of the parts are the same between uk and j-spec Supras.
You may think so. The cars do have different specs and each spec has its benefits. Some of the UKs so-called spec advantages are not desirable to many of us.