Flightsafe device: £30. This is a three pin XLR plug with pins 1 and 2 shorted, in red plastic. This inhibits the scooter operation. Cost of manufacture will be about £1.
115mm rubber tyred jockey wheel, 20mm bore: Disability shops: £18. Various other places: about £10.Various scooter keys: Shoprider on/off switch £10. This is standard plastic body toggle switch: £1 from CPC etc. Some old types of scooter uses a standard 1/4" jack plug, shorted out internally, as a key. These are sold for £5 to £12 in disability shops. Some other keys are on standard blanks and my local cobbler with turn them out at £5 each, but if you buy from a disability shop they are likely to be £12 to £15.
Bill