Aliexpress have close to 10,000 rf-nano.
Seems the preferred module for a bunch of chaps over at modezero where they convert old radios to 2.4g system.
According to them, the keywish unit provides best range and reliability for the price.
https://www.aliexpress.com/item/32980796969.html
https://mode-zero.uk/viewforum.php?f=42&sid=8b1b011259d579a06f4c7fc96889a08e