If I were to go for a low end FMIC I would only go for a Hybrid or similar from Harvey Smith (Same as Nige had).
The welding and thickness of the pipes can be very poor on the cheap one.
Bear in mind that a FMIC used to be over £1000 and some of the top end ones are still close to that.
The Hybrid from Harvey is about £350 :
http://www.geocities.com/harveysmith...micphotos.html