You're absolutely correct MB Doc. I'm ceratinly no expert on AC repair or service, but I believe that with the correct tools AND information anyone can perform some AC work themseleves. It is always a good idea to know what you're doing - buy an Automotive AC Repair Manual and/or get the AC Repair DVD from Autozone, always have the proper tools for the job, and always pay attention to the safety warnings in the manual, on the DVD, and on the refridgerant and/or guages.
Here is the website for epa609 cerification, required for any R12 purchase:
http://www.epatest.com/e_609cert.html