Would it be possible to have the first post of this topic edited to include past/possible tourney ideas? I know SG started the thread and it's her post, but it would be useful to see what other people have suggested so people don't repeat ideas (I'm guessing she wouldn't mind, either). Or maybe even make a new locked & stickied topic with only one post that has tourney suggestions.
What about the exact opposite of a cheapskate tourney--instead, run a "High Price" tourney? Maybe something like you can only play cards that have a 5 or greater quanta cost (or whatever number people think is good)? Pendulums/pillars would be exempt from this rule, of course. It might also be fun to run during an upgraded card tournament, because some cards might be permitted unupgraded but not upgraded (since upgraded cards often have reduced quanta cost). Quanta cost is just one variable for possible tournaments--a different tournament could be only playing cards that cost an even number (or odd number) of quanta to play.