Here is a link for the group buy.
Alternatively, you can purchase them from any PCB / SMD manufacturing company, by getting the files needed from shaman’s github. There is an order guide, however it’s not really worth it in smaller quantities when there’s a group buy.
When I ordered my cheap focers, I calculated the price for ordering 5 from jlcpcb, with shipping it was about 140-150$, from doomy it was 30€ each + 7€ shipping. But if I had ordered from jlc I would have also had to pay tax on top of this, and for some stuff there is a MOQ, so I would have a lot of small SMD components as extra. Just get them from the group buy, it’s easier, faster, cheaper.
EDIT: oh, and JLC no longer stocks the DRV, so you would also have to get that from somewhere else if you were not purchasing from doomy, also driving the cost up.