As is often the case, without background info, any answer is as good as any other in terms of throwing a dart at a dartboard. If circumstances warrant and you want to buy 50E then the advise to just go to the closest makes sense. If you want to buy 500E then the best advice would be to not do that at all as you would be better off buying on arrival in a Euro using country. Buying a small amount of local currency before leaving home makes sense if you are going to arrive somewhere on a Sunday or late at night etc. in an airport with no BANK ATMs. Otherwise even buying a small amount is not necessary.

Advise is always determined based on the circumstances and if you don't make it clear what the specific circumstances are, you leave it up to people to ASSUME what the circumstances are. That's just throwing a dart at a dartboard.