I can understand your points regarding space issues, and the exterior requiring some attention every couple of years that can turn out to be an expense to BA...
I feel it's a shame that BAA can't create a spotters park like they have done at Manchester.. OK I don't agree with the price it costs to park your car (£4-5 I believe) but a Concorde is on display along with a 146 and the money taken from spotters clearly contributes to maintenance costs.