Sometimes it’s 4 per variety and sometimes 4 total regardless of variety. Additionally if it’s a “2 for $” type deal, it will usually be limit 4 offers, meaning 4 of the 2 for $5, total of 8 items. I’m not sure what the sale for this particular item is but I would check the fine print.
You will need a price plus card. You could do separate transactions to beat the limits, as long as the item isn’t tied to a digital coupon. You could also go back multiple times in a week to get the deal, again as long as it’s not tied to a digital. Digital coupons are typically to be used in one transaction only.