The API is not marked as βpaidβ, which means that it is free to the limit and there are no set / published prices above. If you are using an existing quota or are approaching and want to ask for more, I think it is best to ask about the quota request form. It is wise to ask for a quota to provide several quarters of IMO growth, and if you are switching from any other API (for example, IMAP, Atom feed, DOM hacking), then it is obvious that it is reasonable to foresee all this in advance.
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