I'm a true US 6, and my Matildes are a 36.5. The calves are very narrow. If you have large calves, I'd pass.
I also would NOT pay full price for these. Wait it out. They'll go on sale. They were on sale all over the place at the end of last season...I got mine for 40% off, and they were cheaper than that some places (but I wanted gray). I probably wouldn't pay more than that.