Presidents’ Day weekend is prime time for appliance shopping, and Costco is delivering with bundle savings and member-exclusive pricing you won’t find at big-box competitors. The standout deal is the Vitamix Ascent X2 SmartPrep Kitchen System Deluxe ($549.99 after $150 off). With 176 reviews and a reputation that precedes it, this system handles everything from smoothies to hot soups. For…