This is very interesting. I don't think we will ever do a VIP tour (unless we are also the lucky beneficiaries of an awesome gift!). That's a little more that we can afford to pay.
An observation . . .
I don't know how often the tour guides work. But if being a VIP tour guide is a full-time job, and if $500 is a typical tip, then the guides might be doing quite well for themselves. If you work five days a week with four weeks of vacation, you would earn $120,000 a year in tips alone --- on top of your salary! I strongly suspect that most tour guides don't have the opportunity to work that many days. And I further suspect that it is quite common to receive considerably smaller tips (and significantly less common to receive considerably larger tips). So I imagine that the job is not actually that lucrative. And I don't mean to suggest in any way that the money is not earned and deserved, however much it is. I just found it interesting to contemplate.