Comfy boots are a lifesaver, esp. during rainy days. Your pants, which I'm sure you'll be wearing more than one time, would not get wet and they also keep you warm.
I just got back from Europe yesterday, weather was really unpredictable.
Paris, Venice and Florence were cold enough to wear boots. Rome was hot, as in short sleeves and sandals na ang mga tao.
Barcelona, which is in the same latitude as Rome, I expected to be hot, was chilly.
Also bought just 2 pairs of shoes, boots and comfy ballet flats.