CSP Beam Adjusters - is this a good deal?

Machine 7 have them on offer for £29 per adjuster. Question is:

Is that a good price?
How many do I need?
Anyone in the West Mids area that can fit them?

 

sounds good - which type? Usually 2 (one upper, one lower)

EDIT - sorry just realised CSP from the title - DOH! Yes - you need a pair

 

I like them better than drop spindles, does not open a can of worms. They are easy to fit