Guys keep in mind he's an Aussie.. $400 AUD = $274 USD right now.
That being said, I once scored a beat up MIM jazz for $250 USD with some chips in the finish that had some shoddy electronics.. replacing the pots was a pretty simple and inexpensive task, though I let my dad do it because he's pretty handy with a soldering iron.
I paid $250 USD for my MIM Strat as well.
For reference, a brand new Sub Stingray in the US goes for $299 USD, though you guys tend to have a pretty hefty import tax, so I'd imagine a NEW SUB in stores on your continent would reflect that, but if any stores on your continent carry them, I'd check their prices for reference to see how comfortable you are shelling that out for the SUB Ray 4. Used should offer a significant discount.
I couldn't find a Sub, but using an Ibanez SR300e for example, brand new $350 USD over here, $599 AUD @ Big Music Australia.. so $400 AUD for a used SUB doesn't sound bad at all if it's in good shape.