That's quite a nice plate, the thing with plates is the price you see them advertised for is never the price that's paid. Whilst you can advertise it for whatever you want and just take the first offer you get that's reasonable.
A friend of mine as a fairly nice plate for sale think it was 2 JPY or something, he wanted £2k for it, but put it up for £5k and got £2k pretty easily for it. I think if he has advertised it for £2k he would have got silly offers for it.
Having said that I don't know anything about the plate trade, I've never even had one myself and don't like getting with part exchanges that require a plate change if I can help it.