On my mates bike needs changing, he's been quoted 120 smackers inc labour, does that sound about right. Thats about half a days work. Also how hard are they to change, might give it a go myself,had a look in the old Haynes manual and doesnt look that badda job.
Depends very much on the bike, but £120 sounds prety reasonable to me, particularly if it is something with with lots of bodywork to remove. Tell him to be a bit more gentle when landing from wheelies - this is the prime cause of knackered steering head bearings.
See what price they will do it for if you remove the fairings etc , i always take the side panels off the kwack before i take it in knocks about £40 off the service cost ,and i know they are not going to be damaged wrapped in bubble wrap in the garage