Your price could simply be an interface that both Student and Employee implements, and at the call site, you simply call foo.calculatePrice - Student will calculate it one way and Employee another, there is zero need for inheritance, or for the call site to know which object is which of the two types - all it needs to know is it has the calcultePrice interface.

I also prefer pattern matching over dynamic dispatch. But I maintain that conjuring up attributes out of thin air (which is 100% what you're doing when your function accepts one type, and then inside, conjures up another, that has additional attributes from the input!) is insane. There are so many good reasons not to want to do this I don't even know where to begin. For one, it's a huge footgun for when you add another type that inherits - the compiler will NOT force you to add new branches to cover that case, even though you may want it to. Also, such "reusable" if this then do this else do that methods when allowed to propagate through the stack means every function is no longer a function, it's actually *n functions, so ease of grokking and maintainability goes out the window. It's much better to relegate such ifs to the edges of the system (eg the http resource endpoint layer) and from there call methods that operate on what you want them to operate on, and do not require ifs.