Peter - I can only comment about UK beekeeping. The reality in the UK is that the vast majority of beekeepers are either hobbyists, or - to use an American expression - 'sideliners', meaning that they run (say) 30-100 hives, selling honey to friends, via the garden gate or at markets, and maybe sell a few nucs each year.
The number of commerical beekeepers in the UK - meaning 500+ hives, and cropping honey by the ton to be sold wholesale - are very few indeed, and tend to be family businesses, so the sad message is that there are very few opportunities for seasonal beekeeping work within the UK.
The impression I get is that those countries with much larger and less intensively managed rural areas, such as France and Spain, will tend to have far more beekeepers operating at a commercial level.
LJ