Subsidy is for OUT only, thats to have the targets in the ATC system and to ensure RPT get TCAS from the combined ADSB/Mode C fitted lighties.
Exactly, Jaba! Anything more than that should be at owner's expense. For VFR GA ADS-B "IN" is eye candy. Personally, I would fit it in a heartbeat considering my turf is fairly busy around the ML basin.
Creampuff, the gear IS available, it just doesn't come from the US. Check out SELEX and Funkwerk for TSO gear for GA aircraft.
1090ES is the world-wide standard! Not UAT or WAMLAT or VDL4 or....