Four of the five products here are priced per group, and platform pages display that number the same way they display a per-person price. Everything on this page follows from dividing it by your party.
Run the reference product through it, and do it with the entry ticket included so the comparison is fair. On the same September date that walk costs $323 for one person, $346 for two, $403 for four and $559 for six — the group rate steps up past four, it does not stay flat. Per head that is $323, $173, $101 and $93, against $57 for the cheapest scheduled walk. The gap closes from roughly six times to under twice and then stops closing. Nobody should book this to save money; they should book it because the guide answers their questions rather than twenty other people's.
The other thing to weigh is evidence. Ratings here are the strongest on the site, 4.8–5.0★, but three of the five products have fewer than 250 reviews and two have fewer than twenty. A high average on a thin base is a promise rather than a record, and we would rather print the base than round it away.