Buying a cheesecloth

I was thinking of buying a cheesecloth, and I was wondering what to look for in a cheesecloth, and what type of store would have cheesecloth? I don't know how often I'm going be using the cheesecloth, so I don't want to spend too much.

I'm thinking of using the cloth as a strainer for washing my rice and steel cut oats. I was also thinking of trying to make my own butter, and using the cloth to separate the curds. Would the above be good enough reasons to buy a cheesecloth?