I had another one a while back, but in the end the joke was on them.
Saw a handheld battery spot welder for ~12,50 and thought now that is cheap, so added it to my basket and kept on shopping. After an hour or so I had found the rest of what I wanted to order and went to checkout, only to notice that the spot welder deal had expired. The price was back op to ~40 euro, while others offer the same or similar for about 25 euro. So I thought sod it, will delay shopping to the tomorrow.
And the joke is that it was back to ~12,50 the next day, so I directly bought it and 6 days later it arrived and works like a charm.
With the choice items the bonus is the free shipping when you buy three different items or spend at least 10 euros. So that is what I do now. Fill my basket with choice items only and wait until I have 10 euros worth in it. Still look for the cheapest offer of course, but it saves at least 2 euros on shipping. Another bonus is the fast shipping of 6 to 12 days guaranteed. Bonus euro per item if late.