it's a name that wont sell itself..
who is the potential market? php developers? they'll use their own site for blogging or a blogging site..
I think all the *blog*.com sites are only valueable if some buyer is trying to make a blog with serious content and need just the keywords you have in that domain, otherwise they could just make up another similar name like "phpdevblog.com" and reg for $8
just my 2c