Well I have just spent the last hour reading this thread from start to finish, and found it very interesting. HUY is my local airport and when I use it i like it, but, as I pay for all my own travel now in general it is an expensive place to fly from. I used the Air UK flight to LHR on a regular basis and it had good load factors with most passengers travelling onwards, naturally when KLM bought Air UK they didn't want to support LHR. I wrote to BMI and suggested they extend either the LHR/LBA or LHR/EMA flight on to HUY twice a day, they had the decency to write back and whilst they thought their was some merit in my suggestion because of the extended time the aircraft would need to come to HUY by the time it got back to LHR it would have lost it's time slot. I still believe the business community would love to have a London connection, probably LGW rather LHR.
Getting back to cost, apart from good deals into Europe with KLM in the summer other destinations are usually more expensive. Long haul through Schipol is generally more expensive than LON or MAN, charter to Spain is almost always cheaper from LBA,MAN, Stansted etc. This includes taking car hire to the distant airports into account. So far Donny hasn't been cheaper than HUY on common destinations, so I ain't going there..
Surprised about the one percent usage by South Yorkshire, on the odd occasion I have used HUY to Spain I seem to have been surrounded by Barnsley lads on every flight...
My gut feeling is that HUY will continue in it's niche with slow expansion, but, you know the old saying... When change is made it will usually be a surprise and little to do with what the pundits are suggesting!!!!!
So much for my two penneth.....