Yeah I didnt really check the "MC Rarities" part. I've changed stuff. Derelict vouchers are worth an easy 1 mil, due to the rarity of finding someone willing to sell one to you, not to mention the time it takes to acquire all of the rupees without just buying everything for $200.
I forget, when were the promo instructions available? Given that the Eggnog voucher is only good for one promo (unless I forgot what it does lol), I find it hard to believe that it's worth that much, it's worth as much as the most expensive current promo available on EMC, but it's price tops out at that, unless you want to throw in a little extra for having the choice of what you can redeem it for. The Marlix armor I agree on though.
Erm... I don't think the Eggnog is priced based on it's actual promo trade value. It is more priced depending on the rarity. Like the ore buster, it can get you a hell of a lot of diamonds, but those diamonds won't be worth nearly as much as the ore buster itself.
The Wiki is your friend http://empireminecraft.com/wiki/promo-instructions/ The Eggnog is worth at least one million rupees for sure
Caden already said how. It's a very rare item, so it's worth a lot more. After some were used, it's become even more of a rarity, so the price went up pretty dramatically.
Low quantity + Special (renamed, coloured etc.) + Interesting use + High demand = Price goes up Maths, huh
