I think they tend to be about average compared to other tour groups as far as cost. They tend to stay in adequate, but less "gilded" chain hotels, which is fine with me; as long as they are in a safe area, and clean. The restaurants I would rate as just average, but some meals are always open for free choice. I have not traveled as much as most of the people on the tours, but they ALL had been repeat tourers with Road Scholar, for years, which says something positive.
What I pleasantly found on each of my tours was how varied the fellow tourers were in their backgrounds, mostly professionals, smart, and unbelievably outspoken Democrats! They loved all the same things I do: history, museums, art, culture, with well-prepared guides in each place. Also, the groups were all smaller than most tour groups, with about 20-25 in the groups I toured with. I'm afraid my overseas travel days are over, but I highly recommend Road Scholar. Also, not everyone is as ancient as I, although some were more decrepit, but most of younger retirement age.
Anyway, you were concerned with cost, but you get what you pay for, and I would consider the quality of the places visited and the tour guides as more important than gourmet food and deluxe beds, but that's just me.