In New England, apple pollination pricing seems to range from zero
to $75 or maybe a bit more.  Factors to consider are:
1) Do you have to move colonies in and out, especially on short notice such
as a call at 6 pm saying "we are spraying tomorrow at 4 am so you should get
your bees out"?
2) How far do you have to travel?
3) What colony strength are you committing to provide?  I know how many
square inches of brood I need on April 20 in order to deliver strong
colonies on May 15.
4) Are you going to operate your bee business to ensure you can deliver your
standard strength colonies in future years even after heavy winter losses? 
In other words, can the grower count on you?
5) What extra 'features' do you provide that either increase pollination
effectiveness or make the project easier on the grower?
6) What are the grower's other options in terms of native pollinators,
keeping his own hives, or working with other beekeepers?
7) What are the grower's needs?  Some have trouble selling even a mediocre
crop while others want to maximize tonnage.  Some have tree layouts or
varieties that are difficult to pollinate well.

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