That has always been the rule here is NSW. The only place where plates can be easily sold on to anyone is VIC or WA. It's always been through family members or relatives here in NSW because I used to have LL00LL as a joke plate on my old Z3 and was offered $5000 for it however couldn't sell it to him as he wasn't related to me and there is no actual way around it....because you have to prove you are related by birth certificate, marriage certificate etc. However you can always try to submit the form by claiming your 2nd or 3rd cousins and that may work?
Be warned that when you surrender plates it takes a full month for them to go back into the system for being available or sometimes the RTA actually keep the plate aside if they like it and will sell it as one of their "top 20" plates on their website.