Type Four is a pretty interesting format to play, and I still slip in games with it a few times each week
We have tons of data on how many fetchlands are played in Modern (Shocklands) and Legacy (Dual Lands), as well as what effect they have on prices
What do you think of Brawl
You can cast this by exiling a blue card and paying one life instead of spending mana
With all this in mind, the only card where my method of buying in about three months later, when Rivals of Ixalan was released, that is a clear failure is: Spell Queller
Unfortunately, trading is one of the aspects of the game that is the least engaged with from the community, which is a shame and thanks to some of the decisions WotC has made recently, trading has become more difficult