Hmmmm? Over here I would also estimate on "the sum of the parts". For 500 I would expect to buy a 100%-matching M96, not a "nearly all-matching" one. But an enormous plus for an original Ajack.
So something like 1500 Euros plus to 2000, the plus depending on how good the whole assembly really is. For that kind of money, you really, really need to arrange a test firing beforehand, even if it means a long drive. And if you've got more than 2k to spend on a made-up sniper, then you are in the price class where you can start thinking about saving up for a 100% original. But caution - a friend has an original Swedishsniper, and having been fairly well used, it does not shoot as well as his normal M96, which probably had a lot fewer rounds put through it. If you are really keen on accurate shooting, then the made-up one may be a better choice.