Paying for a practice ILS is nothing new. I vaguely remember Essendon and Avalon charging GA aircraft for practice ILS's about 15 years ago (probably still the case now). Of course it's much easier to track who's doing the ILS when operating in CTA and charge them accordingly. I'd imagine in class G, you'd have someone listening on the CTAF frequency for inbound calls with a cash register till beside them.