If you type the whole command (/auc start x y z) and don't have enough items (for example you type 2000 for the amount but only have 20 stacks in your inventory) it'll say you don't have enough and not let you start an auction. If you change the quantity or get more of the item and try again it'll say you have to wait 5 minutes before starting a new auction, so you have to wait before starting despite never starting any auction in the first place.
This is correct. It is because the auction start command itself is on cooldown. @JamieSinn please verify. At this time I don't think I will be getting @JamieSinn to alter how the cooldown works, and will instead keep it at the command level. Please take care when starting auctions and ensure you do so correctly.
you can do /auc s all x y z to avoid having to make sure you got the right amount. this will auction ALL items in your inventory of the type you are holding.