Rare as hens teeth! £215 here is the cheapest I could find. Soper Lincoln with forum discount is a little more
https://www.mlperformance.co.uk/products/genuine-bmw-61316940989-e85-e86-cruise-control-switch-inc-z4?variant=43977896460509¤cy=GBP&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=Cj0KCQjw9vqyBhCKARIsAIIcLME_IMzMgBkYgY2opG63bcxr0WrtZcKouga8EMLof_Yw7y5Ev5Rctw8aAg5wEALw_wcB