That adjunct pay seems low but not unheard of. Here is a thread I found on it [1]. The cost per student per class is not far off (at least at my state school). Assuming a 3-credit undergrad class at Penn State @$800 ($2400) [2].

[1] https://www.reddit.com/r/Professors/comments/un7uei/average_... [2] https://tuition.psu.edu/tuitiondynamic/tabledrivenrates.aspx...