I just ordered my Stratus transponder for the plane. Schedules are already out to mid February for installation.
There are thousands of planes that have not had the installation done. I expect the techs are gonna do a lot of overtime later this year, and that some plane owners are simply gonna have to either not fly, or do VFR-only in uncontrolled airspace at the end of this year.
$2700 deposit for the unit. about half that for installation. I paid for the unit upon scheduling.
Better to have it than not, and risk the fines.