Flashpoint- Holy wallet eating event Batman!

so i just saw the list of tie ins that Dc released for the summer Flashpoint event, and i just want to ask people who probably know more about it than me, is it all needed? do i need to buy every single issue to completely understand Flashpoint? i know they're called tie ins, but are they really necessary? does anyone know more about this event? cause i'm willing to buy them all, but if they all aren't needed, then i thought i'd do myself, and my wallet a favor and skip out on some

I'm not reading Flashpoint, but I challenge you: find me a comic event that isn't wallet eating.

I think there're around like 45 total issues with all the tie in books. It wouldn't be so bad if some of those were ongoing titles such as Batman, Superman, etc, but the only ongoing title involved with Flashpoint is Booster Gold. The rest are all 3 issue minis and one-shots. I don't know how DC would expect people to buy their regular titles and then shell out enough money for 45 extra books over a 5 month period.