I’ve had 2 girls sharing the

together a few times at an AMP. It was always on the way to FS with both though & id seen them each at least once before.
TBH this wasn’t my fantasy, so I tend to remember the FS part of the sessions much better.

Your fantasy is definately achievable (depending on your definition of “reasonable”) at many AMPs. Just tell them what you’re looking for & how much you will pay.
From memory I paid $300 for FS with both girls on top of the shop fee somewhere around $100. This was a while ago so might be slightly more now.