Actually the question is which will give you greater return for your effort. In High School I learned what I call TV German, which would be perfect for a conversation with a TV.

Since then I've tried with varying effort and success to learn Italian and Spanish. When I try to speak either one, there's no telling which will come out!
Bavarians and Austrians have a funny accent, and they kind of "mush the words together". If you speak textbook German they will try to speak it too, which improves your chances of understanding them. Swiss German for some reason is pretty close to TV German. The Swiss usually don't know English (they have to learn French, German and Italian for school, which leaves little room for English), but there are so many guest workers there, someone will know English. Every shop clerk seemed to be Canadian or Australian. I was in the Italian part of Switzerland once, and had an curious conversation in German with an Italian mechanic about the warning light on the rental car.
Usually the best approach is to ask, "I'm sorry, do you speak English" in the local language.
The use of the word "but" usually indicates that everything preceding it in a sentence is a lie.
E.g.:
"I believe in Freedom of Speech, but". . .
"I support the Second Amendment, but". . .
--Randy