Save your money. If you can translate to English, then you can be the translator. Anyone can certify the translation of a document if they can do it accurately and complete a certification form.
The certification form can be quite simple. A suggested format by the USCIS is as follows:
Certification by Translator
I [typed name], certify that I am fluent (conversant) in the English and ___________ languages, and that the above/attached document is an accurate translation of the document attached entitled ______________________________.
