The improvement in safety will pay for these things many times over and again.
If a small operator can't afford $2 or $3k to outfit their aircraft, then they shouldn't be flying anyway!
Mate you obviously haven't installed new TXPRs and new GPSs in an IFR aeroplane.
GNS650 installed by Eaglecopters was $30k, new Trig TXPR about $4k - as installed over 3 400-series Cessnas.
I don't mind installing new gear but yes it is a major cost.
Dick - Good luck with your campaign to remove this requirement.