It's a bummer to hear... but at the same time it's for the better: With the dedicated attitude to the hobby that you have, you deserve to have the X-7 go in the books as a beautiful car, regardless if it remains a concept or makes it to production (though I'm sure everyone will love to see the latter)!
And let's not forget, who knows what the future will bring in terms of production technology. If you ask me, it's reasonable to expect tooling costs will drop in the future. 3D printing has opened a whole new world to mould making, and with the rate of developments and patents lapsing on key technologies in the upcoming years their potential will grow and the costs will reduce