Does anyone know a reasonable place to get an official Thai 1 page certificate translated into English? There are only about 30 words on the page and the one place I found that will translate to English via email has a minimum price of 450 Baht.

450 Baht doesn't necessarily have to be a bad price. It depends on what you get for it (apart from the "obvious" and hopefully correct English equivalent of the Thai language). What do they deliver? Just the text translated, or the "same" certificate in English printed on proper paper? If it's just the text, it's rather steep... Just make sure the translator is a reputable person/company. Ask for a few translation examples; they will give you an indication of their level of English. But then again, who says the examples are their work?

You could try http://fiverr.com

Like this one here - http://fiverr.com/octerber24th/translate-english-into-thai-or-thai-into-english