I dare not comment on 1v1, but in team games, marketplace definitely is way too powerful. Since items drop all the time, you can keep equipping your heroes with the best stuff. Theoretically, you can even research Backpack and have a unit farming items from it, though I've never seen anyone do that.
According to what
@Nudl9 has argued, ideally this would be best at contest launch so you can cater to judges' tastes.
I've been reading through the various pages of the thread. Man, what a mess, lol. I would propose a judge nomination policy similar to that of peer-reviewed papers. Namely, contests should have a minimum of 3 judges, and their evaluations should be weighted according to curriculum and expertise.
Three degrees to classify expertise should suffice: the notorious, renown melee player is top tier; someone who's accepted as a good melee map maker or player, perhaps even won a few contests, is second tier; someone who's made a few melee maps and/or played a bit of melee is bottom tier. Intentionally, this shelf lacks a «no experience» tier. Those people shouldn't be judges to begin with.
