I once bought a pair of EV Bass bins from a Scottish music dealer online at what must have been a 'mistake' price. List was something like £800 the pair, realistic prices around £700 although one place had them for £680, this Scottish based dealer had them on their website for £450 including delivery.
I snapped them up, a couple of days later I told a mate about them, when he went to buy them they were at £700. I think someone there must have made a bit of a cock up. I'm just guessing though, they sent them and all I paid was £450.