It costs time to write the code, yes, but the liability of that code existing will cost an additional, unknown amount at some indeterminate time in the future.
Or that code existing will bring an additional, unknown at some indeterminate time in the future, cost savings when you go to implement a nearly identical feature and you find out you won't be needing to start from scratch as you already have all this well tested, named and organized code to pull from as you craft a new solution.
Your perspective just needs a shift from negative to positive.
