I have just installed this product and see that Google is a paid service. I also see this is what they quote as being the cost.

Usage fees:

Translation:
$20 per 1 M characters of text, where the charges are adjusted in proportion to the number of characters actually provided.
Language Detection:
$20 per 1 M characters of text, where the charges are adjusted in proportion to the number of characters actually provided.
The thing is I have no idea what this may run into per month so if anyone could give me an idea as to what they are paying per month it would be appreciated. I know that this would also be dependant on the traffic to your site and would vary from site to site but I really need some type of a benchmark for this If possible maybe you would also indicate what type of traffic your site has or just post a link to your site and I will try and compare it to my forum