Well, a couple thoughts come to mind...
Your original premise was..."But I want to use a style of track that Billy and his Dad can go to their LHS and easily purchase." I suggest that not all of the track choices are stocked/sold by their LHS. Due to the plethora of choices, the limitations of store space, the cost of inventory, the widely variable turnover rates of certain track brands, etc., etc., we (LHS) have been forced to limit our floor stock to those few brands having the strongest regular sales appeal. We can most certainly obtain/special order most any brand/style (Except Menards' exclusive), but that doesn't fit the "easily" criteria.
Secondly, if you're doing this to attract new Billys & Dads, I would think the display board of all brands of O3R track will be rather confusing and, well, premature. Entry level hobbyists typically will start with a set. I would think their interest in, say, a Lionel starter set featuring FasTrack, would set up a confusing purchasing decision after a Track Choices 101 review/discussion might leave them preferring a different selection. While dealers may give a price credit for eliminating the set track, this goes back to the question of "easily" obtaining their preferred alternative.
Most of the track choice discussions on this forum really end up being a 'TEHO' issue. And that's after some deeper experience into the hobby, seeing other layouts, understanding through experiential discussions the pros/cons. Some of the issues are budgetary. Others can be that issue you brought up....what's "easily" available to purchase....locally, if possible.
But, your choice......of course.