I recently added oven chips to an online shop, not realising they weren't pre-coated with oil.
Given that I prefer skin-on fries why do they always cost more? I'd effectively bought a bag of expensive sliced up potato.
On the plus side, it has made me realise that buying oven chips is a total waste of time, particularly as I have very limited freezer space.
What's the daftest "convenience" food have you purchased before realising it's a total waste of money?