The £2.50 charge for drop off at BOH is a drop in the Ocean...BLK have a £10 ADF fee offset by free parking up to 14 days. I think there is a free short while without fee for a drop off, not sure though.
The point being that airports like BOH, BLK and other regional airports need extra cash to operate in an economic dip like we are in.
I really can't see why there is such a fuss over a couple of quid - I would gladly pay that, if BOH where my local airport.