People will need to make a habit out of *VIDEOTAPING* the opening of all their packages, if such scams start becoming widespread.
That way, you'd have proof that the box either contained nothing or did not contain the item you ordered.
Also, the reputation system should hopefully help you identify scammers before you order from them.
Well if the reputation system ever goes the way of eBay's, it will become worthless. You used to be able to identify scammers more easily on eBay, especially from buyers.
Also as a frequent seller and buyer on eBay (over 2000 feedback), I have seen way more attempts of scamming from buyers than sellers. Actually, I do not think I ever have been outright scammed buying something, there were a few times I had to open a ticket with a seller, but all of them were resolved properly by the seller.
I have have had maybe 30 tickets I was forced to deal with due to buyers claiming they did not get an item, or item not as described, with half of these outright deliberately trying to scam me and the other half at best not properly reading the description (i.e. expecting new when item clearly states used with any flaws described).
If the item is of significant value, I would suggest videotaping as you describe, not only for buyer but the seller as well as they pack the item. Another option as a buyer, maybe even as a seller but I have never tried it, is to open the package in front of a witness, such as delivery person, or hold packages at the Post office, etc and open them in front of the counter person to witness if it is a empty box or rock, etc. I suppose a seller could have everything ready and finish packing/taping the box up in from said counter person and see if they would sign affidavit.
Anyway, the point is scams can occur on both sides of the trade, so don't assume it is just sellers.