Re: Southampton
Alternatives are Lee-on-solent in Gosport.........(might find info by doing a search for HMS Daedalus). Recently became surplus to the navy and is now primarly civilian. Not sure about prices, but it's likely to be much cheaper than £200 for 2 days.
Further afield you have Goodwood, Old Sarum in Sailsbury and Bournemouth.....all of which are going to be much cheaper than Southampton. But a long taxi ride.
Southampton recently priced GA out of the airfield........pretty much all flying schools moved out last year, and relocated to Lee-on-solent.