do i get the 40 blueprint at once in 415 gold in this special event

415 gold is the price for 5 blueprints (83 gold per BP).

You can buy up to 40 blueprints from the event shop. That would cost 3.320 gold for them all.

I would recommend that you do NOT buy any extra blueprints. This car can be farmed in the campaign or bought with scraps in the Chop Shop.

I hope this helps.