A bit of constructive feedback:
Someone I know was planning to buy a Pokitto recently but couldn't (because the stocks were so low).
They said that the out-of-stock notice wasn't immediately obvious to them and they'd filled in the credit card details before realising the Pokitto was out of stock.
They said maybe it would be better to make the system refuse to accept credit card details if the chosen Pokitto is out of stock.
From my point of view, I'm thinking refusing to take credit card details for out of stock items would be a good stop-gap,
but what I think would be ideal is if the site had an option to reserve a Pokitto of a certain colour combination
(at which point adding credit card details for an out-of-stock Pokitto would make sense).
That way when you come to create the next batch, you can fill the 'reserved' orders first and it would give you a better idea of how many of each colour to make.