Hills are never good as a question because there are several types of hill. The biggest problem relates to size. If you want a hill that allows a single unit occupancy you are laughing, but most times hills are much bigger, sometimes they can be features that extend along a whole side of a battlefield.
In short, when it comes to hills the question is a matter of troop scale. Answer this question before you proceed and you will not go wrong. In essence, it is do I want a land mass or a pimple?
Sorry, because this might not help, but I introduce it as food for thought - don't waste money on pimples if you want proper hills.
I recently set up a battle set during the SYW, this is quite a small battle, but the hill size might be food for thought.

In this shot the two hills, except for the valley between, extend for almost the whole twelve feet of the Prussian deployment. Hills are big.