Pinching pennies clearly isn’t Meghan Markle’s strong suit. Since she and Prince Harry, 33, announced their engagement in November, Prince Charles — who bankrolls both his children and their spouses — has spent a reported $1 million just on the American actress’ designer wardrobe. Unlike thrifty Kate Middleton, who often wears Zara and other high-street brands, the newly minted Duchess of Sussex, 36, has “expensive taste” and it’s breaking the bank, a source tells Life & Style. In June alone, Prince Harry’s wife stepped out in an $18,000 Givenchy cape dress for her first solo engagement with Queen Elizabeth II, purchased a $4,000 Carolina Herrera off-the-shoulder top and skirt for the Trooping the Colour ceremony and arrived in a $6,000 Oscar de la Renta printed maxi dress for Princess Diana’s…