Because the cost of labour varies dramatically from country to country, region to region, city to city and sometime even suburb to suburb it doesn’t make much sense to ask how much the labour portion of a clutch replacement should cost, but it does make sense to ask how many hours labour would be involved. 
There are probably 4 different setups that may (or may not) have dramatically different answers.

 1. Front Wheel Drive 
 1. Rear Wheel Drive 
 1. Transverse Engine All Wheel Drive
 1. Longitudinal Engine All Wheel Drive

So for each of these setups (and any others I might have missed), Approximately how many hours of labour would a professional mechanic be charging for when doing a clutch replacement?

Obviously there will be a fair amount of variance between different vehicles, but I’m just looking for some approximate guidelines.