This question has been closed as off-topic. The basis for this is the area51 proposal where "Where can I find the lowest prices on [electronics/furniture/etc.]?" was specified as off-topic.
I think we should explore where the boundary is. I can see why "Where can I find the lowest prices on X" is problematic, because the typical answers will be about the merits of various retailers which is really veering a long way from the managing your money.
However I don't think the closed question about airline tickets falls into the same category, because useful answers will tend to provide general advice about how to plan your life to save money.
So...is closing the airline tickets question really the right decision? Can we characterise what is and isn't ok in this area with more examples?