I purchased both alchemy and legendary potions at 50% a little over a week ago. I would have gone at 100%, but I couldn't really afford it. I have yet to strike gold with one of these, but I have seen a couple legendaries show up. Certainly at a greater frequency than I would otherwise have seen. Here's a look at some of the things the legendary potion brought me.
So, a couple of legendary Black Dragons. Very useful in the battlefield when my daily Quest splinter is unavailable. They are legends, but not quite to the Will Smith I Am Legend level. But it gets better.
Nice! Lord A makes an appearance. But wait, it gets even better. We're about to get into Tom Cruise Legend territory.
Boom! Minotaur Warlord. A card that's worth money that I have absolutely no use for on the battlefield. This is almost best case scenario. My Lord A is already as maxed as my summoner levels would allow, so he and the Minotaur took a trip to the marketplace and went home with new owners, and I increased my Steem.
I feel like the jury is still out on whether it was worth it to buy those potions or not. In order to get enough DEC, I burned all of my gold rewards cards that I wasn't using. I suppose I may kick myself in the future if the card prices recover, but honestly as common as reward cards are I don't see them gaining much value in the future. But I definitely got some nice cards that I theoretically would not have gotten if not for those potions. I think it will come down to what my next openings bring until the potions run out.
I've also been using the DEC I earn for my daily quests to buy orbs. I think the orbs are giving me some useful cards, specifically the armorsmith is a real thorn in people's sides, if he can stay away from magic Blasters. Armorsmith has been a big boon to white, a color that sorely needs some help.
So with the potions and the orbs together, I feel like I've got a pretty good thing going and hope to uncover some legendary gold soon.