I am going to buy but I don't know when I can do it on the crazy weekend or do it on tanki birthday they are both good days but which one is better?

But what is better this event or tanki birthday

Should I buy now or wait till the April event if I buy now I will get 716,000 crystals but if I buy on the event day I could get somthing else and what kit is the best for M3 so I can get ready for it, with alts.