My apologies - the figures I quoted above (ie $24,000/$52,000/month) are for JFOs and above.
To clarify:
SOs with up to 2 years service get a base rate of HK$14,000/month or 50% of the RFZ if they take out a lease, ie HK$26,000/month.
SOs with more than 2 years service get a base rate of HK$18,000/month and the full RFZ (HK$52,000/month) with a lease.
Still, that's all a bit academic. I agree that HK$24,000/month isn't nearly enough to provide a reasonable standard of accommodation for a 'western' family moving to Hong Kong.