I am sorry if the add-on disappointed you.
I can see that you've been trying to translate very large amount of text and hit the free trial limit. The actual paid plan's limit is much higher than that of the trial, and it should be enough for most use cases.
However, since your use case is somewhat extraordinary in the amount of text you need to translate, I'd like to ask you to let me know what kind of work it is you're doing and how much text (in words or characters) you are expecting to be translating throughout a month.
You can email me at the address in the from field of this message.
Thank you,