Zavvi offers Police Academy: The Complete Collection on Blu-ray for $13.21 (£10.79). With $1.21 for shipping (£0.99) , that's $3 under last year's mention and the lowest total price we could find by $8. This set includes all seven films and behind-the-scenes features.
Of note, new customers can apply coupon code "WELCOME" to cut the price to $11.89 (£9.71).
This Blu-ray set is region-free, and the films themselves will play on US Blu-ray players, however the extras and special features may not.