Your timing is about 1,5 weeks too late. You missed out on Holo's huge anime mouse pad fundraiser sale.
Well, watch the Doki main website and possibly
this post closely on Saturday when Holo updates: "Most mousemat orders have been posted ... I’ll post an update on the stock levels at the weekend. Those of you who have not paid and also not bothered to answer my emails will forfeit the reserved mousemats on Saturday, when I post update." So you might have another chance if you're quick on the refresh button on Saturday.