When I was still working, I often buy branded shoes but leaves it in the office. I often wear flats the rubber one like Melissa shoes or sometimes just a regular flat shoes. Sometimes I wear rubber shoes when I know that I'll be walking out for a long time and just change in the office. Aside from being much comfortable walking in flats it is much more beneficial on your end. Just keep the branded shoes in the office and have it ready when you need it. Besides rainy season will just be for a couple of months then it is for you to use the branded one when the rainy season ends. Just make sure to choose a shoe that will always be on trend. ;)
I don't buy expensive shoes. I prefer to have a lot of cheaper but quality ones instead of a few luxurious ones. For rainy days, you might want to try jelly doll shoes like Mel, Grendha and Melissa. They're comfortable and rain-proof. Might be a little expensive but it's worth it, considering inclement weathers
well, it depends where is yr office. if accessible by walking underpass, very minimal contact with rain, why not? even if u get in contact, just ensure you dey it properly and it will last. most importantly is the comfort