Anyone know how I can buy single satellite - rbs750 or 850?

[gtp130]

Looking to add another satellite or two to my ax4200 wifi6 mesh (1 router and two satellites already working fine). Can't seem to find anywhere (amazon, the box stores). Any help is appreciated.

[FURRYe38]

https://community.netgear.com/t5/Orbi-AX/RBK-753-satellite/m-p/1939859#M4978