The final countdown is underway for holiday shoppers and, if you’re holding out for a Christmas Eve shopping spree on the theory discounts will be plentiful, think again.

Consumers this year are likely to score big bargains on Friday, Dec. 21 — when, figures from last holiday season show, 40 percent of items dropped in price. But shoppers who wait until Dec. 24 will probably pay — literally — for their procrastination, as they did last year when retailers marked up 40 percent of products by an average of 15 percent on Christmas Eve.