Report lowest "playset" price

In addition to providing sellers (and/or buyers) with pricing data for single cards, provide the "lowest playset" price, potentially as a second "Buy Box". For example, what is the cheapest total cost for 4 copies of a single Magic card from 1 seller.

Note that different games may have different quantities constituting a "playset" e.g. 4x for MTG and 3x for Yu-Gi-Oh!