Ditto, I believe the price is right too.
As for building one for half the price, assuming you mean you'd charge the customer around £11,500 and would be in profit yourself, you'd barely be making minimum wage for your time. The customer would probably export it to Europe then sell it on for twice what he paid for it anyway.
There are people out there with deep pockets for classic replicas - Suffolk Sports Cars' stand was swamped with toffs at Goodwood, while the maker of the Aston DBR1 replicas is also trading very nicely in the £70-120k bracket, then there's these:
https://www.ebay.co.uk/itm/Reliant-F...53.m1438.l2649
https://www.ebay.co.uk/itm/Maserati-...oAAOSwVnFbXPoj
https://www.ebay.co.uk/itm/1956-Mase...sAAOSwbxBbQ3ax
https://www.ebay.co.uk/itm/ABSOLUTEL...EAAOSwZZlbomrs
Kit cars and specials, one and all.