I find they vary based on what you're buying. Electronics and wine are never a good deal at TLV. I usually do buy whiskey (or whisky) at TLV, because their prices are significantly cheaper than at Israeli shops, and is also cheaper than other airports (though not by much). I've found them to be similarly priced to liquor shops in the USA, except in those shops, you're getting 750 ml but in James Richardson, you get 1 liter.