I just got my envelopes back from the calligrapher we used and they're perfect! We used Michelle Dowling (
http://www.ctcalligraphy.com/) and she was great from start to finish. When we first contacted her she got back to us in just a few hours. She did a sample for us before we decided to use her. Once we sent her the list of names and addresses, she contacted us twice about questions since the outer envelopes and inner envelopes didn't match perfectly and wanted to know what to do before proceeding. She even remembered the name she did on the sample for us and asked if we wanted it done again since it was still on the list! I believe she charged $1.50 for the outer envelope and $0.25 for the inner envelopes.
I'd definitely recommend her!