I am curious to learn how I would set a value to round up to a particular number, if it is below a certain value

So, I work as POS admin, and make sure our buyers have accurate pricing data. I had a request to build a formula where I would take a number, say $9.47 and round up to $9.49. Now, the request is also to round to .99 if the cents value is .$50 or over. I have no idea how to go about writing the syntax for this and any help would be appreciated.