I've had that once, apart from regulars who know the deal. Just the HJ, no discussion on cost, but standard 1p paid. Became a semi regular after that.
I find some older Thai MLs often give strong hints. Like stretch your arm out to massage it and clamp your wrist between their thighs. Or place your arm on the table palm up and then very obviously lean over and place either their breast or thigh right on the palm. Leaves you knowing that options are available without whispering you want extras? And your wandering fingers let them know you are receptive.
One of the benefits of an older ML is their confidence.