A budget construction cost estimate has been prepared for the Phase 1 development of Goodwin Airport with three runways. Costs are based on 2012 prices. No allowance has been included for land acquisition costs or for inflation.
Cost estimate for Goodwin Airport
| Item | Cost £ Million |
| Construction of The Island | £3,500 |
| Link To Mainland | £1,200 |
| The Harbour | £1,200 |
| Roads, Rail and Runways | £11,400 |
| Improve Existing Infrastructure | £3,000 |
| Buildings and Structures | £8,700 |
| Equipment and Systems | £10,200 |
| Total | £39,200 |
Locating an airport offshore is, inevitably, not the cheapest option in terms of construction cost but offsetting this the operational, social and environmental benefits of Goodwin Airport are considerable. In due course a detailed cost-benefit analysis will be required to compare shortlisted airport proposals.