How about reading online first before making decision.
http://www.mangago.me/read-manga/claymore/
I have read it long long ago before I read yaoi.
I haven't read the manga, but I did watch the anime and it was amazing. The manga is usually even better than the anime, and in this case it stretches out longer. I would definitely think it's worth the read. As for whether it's worth buying or not, that's more subjective. Do you prefer to have manga in your hands when you read it? I'd think it's worth buying, especially since you can share it with friends and discuss it with them that way.
I am interested in manga Claymore and I want to ask if it is worth buying.