Alrighty now I don't know any card games that don't have this feature in real life or online. It seems like this would have been brought up before. I kinda want EtG to challenge me a little more - make me make decks that I haven't wanted to try to make. Why not replace the bazaar with (or add) packs of cards? You could buy packs of a certain element or go for a rainbow pack filled with cards of every element. Then there would be packs that cost more or less based on if it only has common cards, a rare, or an upped card! Now you could say that the packs should all be the same price and getting a rare or upped card should be out out of shear luck, but I honestly don't think there are enough cards in EtG. Maybe, there can be packs that correlate with the Bronze, Silver, Gold, and Platinum League. You could have a higher chance to get an upped or rare depending on what league you're battling. I don't mean to undermine what EtG has become, but I think this little twist would gain a lot of interest.
-Shrink