Bicycle spares and tools
We don't have very much room in the van for carrying lots of stuff and bicycle tools was one of the things we rationalised down to the bare minimum. Having spent money on a poor quality bike repair because we had not bought the tools required, we ended up buying the tools and doing the repair ourselves; it would certainly have been cheaper if we had bought the tools with us and we will re-think what we take for future trips.
Living in the north of England this has never been much of a problem for us. However, the kettle has needed de-scaling regularly all over Europe. Generally it is difficult to get hold of the chemical de-scalers, as mainland Europeans don't use kettles very often, so in future we might bring this with us. Wine Vinegar is widely available and this works well too, boiled up with some water and left to soak, although the van will smell as if you are pickling onions!