First, you get a 6/6 flying for six mana, but then every enchantment played or Room fully unlocked results in a creature being stunned permanently (or at least until Fear of Sleep Paralysis leaves)
And even if you are not interested in selling, you do not want to damage your property without proper storage
But of course, voting for someone else is promising them extra card draw, so theres a whole gamut of options to consider here
The ramp spell Dinosaur decks needed, Thunderheard Migration is one of the best ramp spells for Standard in the last few years
Conventions offer more competition between buyers, but not everyone there buys bulk, and the lines can be long
This mana can't be spent to pay generic mana costs