Game of Vampires- doable?

Just finished the 1.2 million goal in about six days spending $4, $2 of which I got back from the purchase goal. It took a bit of grinding, but it was manageable so I am considering trying to get to either the 7 million or 10 million goal. Does anyone have any advice?

I’m OK with spending a small amount of money, but I am definitely going to avoid the VIP goals.

Thanks for any help!