Well, it's in Euros which are currently worth more than the American Dollar. It seems like a decent price though.
Yeah, i'm totally aware of that. The price in dollars would be approx. 340. It's just that used epi les paul customs are usually sold here in Europe with a higher price, 400-500EUR, which makes about 600USD : ) Therefore, concerning the normal prices, it's really-really cheap and that makes me kind a wonder.
It's cheap because it's used, and it's been modded. Brand new, an Epi LP Custom will have a pickguard, it won't have that Gibson trussrod cover, and they've changed the pickups too (normally Epi Customs have generic humbuckers with gold covers. Obviously here they've changed those for an uncovered di and 496. This will actually be quite an improvement if you want more bite for harder rock and metal, and it's always worth changing the pickups in the mid-range Epis anyway).

I'd say this is about worth it, if you think the new pickup config would suit what you want to play and if you're not fussed about it being used/modded by someone else already. The other thing is, some Epis are made fantastically, others are average, and some are awful - of course buying online, you don't know which you'll end up with. Really, you need to try any Epi out in a store before you buy it.

If yu think this will suit you and you're willing to take the risk on the quality, it'll be a great deal. Personally, I'd skip it though in favour of getting a new one and modding it myself.