OK, we have tested a lot of game SIM controllers and the BetaFPV Lite Radio 2 SIM controller at $18 is a deal. These are not transmitters, only SIM controllers.  I highly recommend them 'as of today'.  Make sure you get (Mode 2).  Let me know if you have any questions. The cheapest place is to directly buy them from BetaFPV, but keep in mind the tariffs.  I have also found them on Amazon for $39.  We are working on a Discount Code for the future. ~ Cornell