Ralph , its no secret... the gryphon Kit costs $1800.00 the retracts are Robart specially made with exact length Oleo struts and the trike set is $375 the fuel system is Kevlar fitted Fuse shape tank 2.4 litres, costs $125. the kit price includes the dual place cockpit with two pilots and full instrumentation. you can use any 3 3/4 wheels and brakes you want. regards Malcolm