Numerous Lego Super Mario and Mario Kart sets are on sale at Amazon ahead of Prime Day, saving you as much as 30% off the MSRP price. The sale includes big price cuts on sets like the Mario Kart Standard Kit–which is down to its all-time lowest Amazon price of $16 (was $20)–and the popular Pirahna Plant for $42 (was $60), among several others, including some hard-to-find kits and a few that are set to retire soon. See all deals…