Brompton owners

I have a friend, I do, honest, who would like to buy a folding bike for 3-400 quid.
In that budget, what's good and what's not?
I doubt there's a brompton going on here for that, is there?

there are many 2nd hand Bromptons for that price.

There's one in the classifieds in this weeks Cycling Weekly. £370 in Humberside