That is exactly the kind of test taking I am talking about.

I spent a little extra through the local Johnstone dealer for the 608 test prep and they tested me also. I think I spent a little under a $100, $79? or so, test fees included. This was several years ago in Bangor, ME. The certification is through Mainstream Engineering Corporation.

This is link to a bunch of exam info at Mainstream:
http://www.epatest.com/

This may be the very kit that I bought:
http://www.epatest.com/q_608certinfo.html

Here is a link to the EPA exam overview:
http://www.epa.gov/ozone/title6/608/technicians/certoutl.html

It is important to develop a relationship with a local distributor so that they will give you the good prices instead of treating you like an outsider and protecting the local contractors. Johnstone is on the high side but they are a nationwide chain and I have an account that can be accessed over the net or at any local dealer. They have some good sales sometimes too.

I bought an expensive book at a local bookstore and later found about the same book at used bookstores for next to nothing. You might get lucky. An older book for the fundamentals is fine, Laws of Physics don't change often. Newer smaller cheaper books for regulations and recent developments may be the way to go.

I still like to read about geothermal heat pumps. I recently read that R134a is on its way out, to be replaced by CO2.

BTW, I think most small appliances are now 134a.

609 MVAC testing is still $15 or $20 and is an open book, online test.