Remember, just because a photographer offers a workshop, it doesn’t necessarily mean that he’s a great photographer. Anyone can “offer” a workshop, but that doesn’t mean it will be money well-spent. I’m not directing this at any one photography workshop – and I know there are several amazing workshops out there.
I’m just saying, make sure you spend your money wisely. Ask around and make sure other people on your same skill level learned something from it, before you go dropping a bunch of money. There is no government entity that regulates workshops, so the only way to know what you are getting is to do some serious research beforehand.