The website you posted is not a legitimate college. It has a .com address, not a .edu, and they are not accredited. Sure they offer classes, but if you ever wanted to transfer credits to a real college or anything you won't be able to. It's basically a glorified 'take my classes to learn things,' and learn you will, but if your goal is to get a degree, skip it. Non-accredited schools aren't worth the money if that is your goal. If you're just aiming to learn stuff casually, go for it. The certificate will look nice, but won't mean much, I think, if you're looking for a legitimate degree.
The fact that it's all online is a flag to me too. Learning about something that is SO hands on completely online seems wrong.
Again - if your goal is just to take some classes to learn more, this seems like it could work. Really look into it before paying the money, though.