I bought a Home One pack and got 10 blueprints and have zero regrets because I... ...READ THINGS BEFORE I BUY THINGS.
Seriously, it took no time at all to find out the following information:
--It takes 100 blueprints to hit 7*.
--You get 15 per completion.
--The event runs three times before switching to once a month.
What is it with people that they just don't understand things? If it says 15 blueprints, it means 15 blueprints. "Bububububut it says 2 zetas!" No it doesn't, you dumb idiot, it says "1-2 zetas" meaning there's a range and it's randomized. If it says you get X of something, then you get X.