"In spending mood", I think that's quite a problematic thing to say. I watch my spendings closely because I don't have so much money so it's either Christmas presents or U2 tickets, both is too much for me. I'd be more than happy if I have more money in January and can pay for tickets then, but ok, you have to take it the way it is anyway.
Well then, you do realise that your spending habits and personal accounting diverge from what is most commonplace, right? Retailers and other sellers don't look forward to December for no reason.
U2 undoubtedly have people advising them who are familiar (obviously much more familiar than you) with how the market works, how to maximise sales, and how to promote a tour most effectively - both within their own organisation and Live Nation. This isn't being run out of a hut in Uzbekistan.