If you want to be noticed then they help. $500/year is a rip off though, its just money in the Governments pockets to 'fix roads'. the $160/year ones are reasonable depending on if you can afford it. Im pretty sure in NSW that you cant auction off standard & custom plates that follow the standard codes (ie: AAA.111, AA.11.AA, AAA.11.A etc.) But full custom ones (ie: all letters, all numbers or a mix thats out of the normal sequences) I think you can sell them.