Low numbers are rarity / wankfest amongst those who've already spent all you can on a car. They're also selling, so hard to argue they aren't worth it; no different to diamonds for jewellery - tiny pieces of rock that do absolutely nothing.
The plates Leigh posted, on the other hand, are people who think their ingenuity in spending days on www.vplates.com.au and snapping up numberplate combinations no one else already wanted should be rewarded with cash, on the basis they managed to make a 5 look like an S and so on. Begs the question how they scraped together the $700 required to buy custom plates in the first place. 88E daytraders? Heh. Heh.