Where can I find/buy long (thousends of keywords) and trustful lists of most
popular and/or top paying search keywords in foreign languages, eg.
German, Spanish, French, Italian or any other popular languages. I'll
pay for the most extensive list of popular languages and for the cheapest solutions.

Maybe buy some dictionaries, no, better, one of the multilingual
translating devices?
If you can give us a list of keywords in one language, maybe we can translate it.

Of course, there are also online dictionaries

i dont recommend helping these people as their intentions are usually
keyword spam...this being a google service and all

to eliteskillsdotcom:

I'm not asking for anything illegal and not going to do anything
illegal. I'm going to prepare international versions of the
clic2find.com site, and need these keywords for "Frequently searched"
lists, so that I don't start with empty lists.