In common usage, infrastructure often is used unqualified to refer to good physical conditions in a community (as, for example, "Our town has the infrastructure to support your robot factory!"), although it implies little or nothing about tax, economic, and labor conditions. Of course one can also say "Their infrastructure is awful!"; that is, "good" is not an inherent quality of infrastructure.
Note, infrastructure is "The basic facilities, services and installations needed for the functioning of a community or society."
Regarding linguee.com, their "About" page clearly says, "there is no other technology anywhere else in the world that compares with Linguee", so obviously you should keep using it. :) They also assert that the translations they provide (which, if I understand correctly, are in this case English to German) are human-made (or at least human-moderated). In comparing the English and German, it seems that the connotation you suggested for the German word (i.e. "conditions necessary for a business idea to work out") do not hold up in these translations; for example, "worst imaginable conditions" going to "denkbar schlechten Rahmenbedingungen".
Forgive me for stepping off topic; but as an old non-profit hack I suggest you stop and think whether that's really what you want to say.
If you happen to know that your donor is a P.G.Wodehouse fan, you may remind him of Wodehouse's fondness for “Every little bit you get added to the little bit you've got makes just a little bit more”; but I would be wary of appearing to rebuke him for having given only “a little bit”.
I suggest a better approach would be something like this (of course I’m making up the numbers; you must be very careful to be accurate):
Thank you for your generous gift of $17.25.
We are now 5.8% of the way toward our goal of $1,000,000. That leaves us quite a way to go, of course; but your donation at this early stage helps critically towards building momentum for this initiative.
If you happen to think of others whom we might approach for support, with whom your name would carry some weight, I would very much appreciate your dropping me a line at the email address above.
Gratefully yours, &c
With any luck your correspondent will jump at the opportunity to demonstrate his connectedness, and provide help that doesn't cost him anything out of pocket. He may enjoy the opportunity to have you hold up his acquaintances and rivals; and he might even increase his donation and give you permission to mention the amount, in the hopes that a base spirit of emulation will increase the bite on them.
Best Answer
This is often described as having "X" tastes on a "Y" budget, where people fill in their own humorous contrasts between something lavish and something frugal.
Two of the most common are "champagne tastes on a beer budget," and "caviar tastes on a tuna fish budget" (this last one was parodied on the show The Real Husbands of Hollywood, where star Kevin Hart was described as having "caviar tastes" but believing that caviar was spelled with a "K").