For the region it is a must it is as simple as that.
Cost - As a Solihull Council Tax payer with a mortgage and being battered by Interest rates I must admit that helping to fund the extension is not appealing. The best way forward would be to sell the airport to a company who is interested in the business and with very deep pockets.
Location - I moved closer to the airport as it is located it a great position for transport (work leisure, family) but was not daft enough to buy a property under the flight-path! I do feel for the home owners who have lived near the airport since the late 60's early 70's but as for the rest
Pete