Didn't he try that and got rejected from a convention. It seems like the sort of thing conventions would be very wary of. There are the obvious copyright issues. It would be purely a laughingstock. And you would risk being criticized for hosting a bullying situation.
Yeah, the Amiibo business model didn't make a lot of sense the way he approached it. The only logical way of doing it would be to by the parts for 5 or 10 Amiibos with cheap inputs, make them, list them, wait until they were almost sold out, buy some more parts, and then repeat until he had satisfied demand.
His drawings and medallions made a lot more sense. Cheap inputs, large markups, enough demand to earn him a decent chunk of change. He did get (I think unfairly) criticized for high prices on those, but they were a decent idea. The main we he fucked that up was by taking unlimited orders instead of either selling premade stock or a fixed small number of orders so he could keep control of his workload.