I took a lesson from Nate Sexton way back in the day (I think 2006?) and it was an incredibly valuable experience, we did maybe 30-45 minutes of field work, then played nine holes together. I don't remember what I paid, I was 15 or 16 at the time, but I remember thinking it was a really good deal. I definitely agree that, if done as a one-on-one lesson, even if just on the course, I would have no problem forking up decent money ($100 for a ~1010-1020 pro, maybe more like $150-200 for a top pro) for their time. As stated above, there is travel, prep time, even coming out for one hour is a decent chunk of professional time. As for whether I would pay $100 in a pro-am setting, there it would depend more on the pool of pros, if there's 2 or 3 big names and then a bunch of local 960-980 guys I think I would need there to be like a solid players pack or a particularly fun event/course to draw me out as an am player. As a historically ~935 rated player it's not too hard for me to play casual rounds for free with guys in the low-pro range.