I bought one off DJI parts website for $37.00 shipped from China to USA and now they're out of stock. Looks like all the US retailers bought them up and marked the up substantially!
Quite a few still on eBay and plenty on Ali but the prices are going up and up and up as more buyers don't realize you can't buy the base kit without the controller (because you already have one) and then when you go to use it, you need the transceiver. Pretty silly for DJI not to include it in the base package (even though it isn't needed) for a few $ more but I get you gotta hit the lowest price possible. No one is going to rebuy the controller in a kit just to get the transceiver so it only makes sense the aftermarket prices are doing to keep going up and up as these standalone items become more scarce.