HELP/ADVICE ON SELLING QLD PLATES

Gaday guys,
l'm playing with the idea of selling my QLD personalized plates, GMH 58.Firstly l'm not desperate to sell them ,so l wont be giving them away,but on the other hand l dont consider myself to be one of these knobs that sells a pair of plates for $15,000.They are doing time in a cupboard locked away & l thought they might be exactly what someone is looking for. l was thinking l would like to get at least $800 for them,any less & l dont think its worth it,you never know l might have 2 FC's again one day!
l thought l'd try you guys first for 2 reasons:- first to give you guys first crack at them & secondly if anyones got any ideas on the best way to see what theyre worth. l've sold a fair bit of stuff on EBAY but so far nearly everythings gone down south so thats no good for qld. plates! They're white letters on dark blue with the front one a slimline plate.
While we're on the subject my wife is thinking the same thing with her plates theyre MIZ 64 (black & white)
Shes thinking something round the $700 mark.Thanks for your help. Daz.