Ignoring the very reasonable price that Amazon UK are offering the core set for I nearly fell of my chair when I saw the price that one of the vendors is offering it for:

(edit: I can't get the link to work, just check out the core set on Amazon UK)

I'm almost tempted to buy another one just because it is such a bargain.

It's a great price, if it's indeed the third edition. If there's a way to contact the seller to be sure that they know what they're selling, I'd do that before buying. It doesn't sound right, because it seems to be priced less than wholesale. Does the shipping price make sense for a box that weighs about 3 and a half kilos?

That price sounds more appropriate for a new copy of the second edition, but you just never know how games fall into sellers' hands. It might be something they ordered or received by mistake. It could be a copy that was opened but never played.