A proper full re-flock involves:
* assessing how the saddle sits on the horse, including when ridden;
* taking the saddle apart;
* removing all the old flocking (or whatever has been used to stuff it before - you'd be surprised);
* putting in the new flocking (and this is much easier said than done), and adjusting to the requirements of horse and rider;
* putting saddle back together again;
* putting saddle back on horse to check all OK, including when ridden, and adjusting if necessary.
This can be several hours work. How much per hour would you expect to pay a professional for a good job? I can do my own, but if not I would expect to pay at least £50. £60 to £80 is certainly not too high for a fully trained saddler.