Okay, I'm a little slow today, maybe, or just easily confused: your initial question is how to pull back, but then you ask if you should VIP? Aren't these kind of opposite? Or are you just stuck in a hanging-out rut, and are looking for any change at all?
Since she's been spending time with you for peanuts, I think it's a decent bet that for real money, she'll show you a great time. Otherwise, if I've been hanging out with Porsche but now I want to see Candy, but don't want to completely blow things with Porsche, I find it's just easier to be transparent. I'll tell Porsche, "Hey, I have an appointment with Candy today, but I totally want to hang out with you next week, ok?". That's it. The way to get her pissed off at you is to sneak around, or ignore her, or make her think Candy stole you, or whatever. You have a fighting chance to keep Porsche happy -- and get her feeling like she should be on her toes a bit, in the process -- is by being matter-of-fact and transparent.