Univ of Vermont Engineering buying books - are they really this expensive?

my son is a 2nd semester Freshman at UVM in engineering. His calculations for books for this semester is around $900. He and I are stumped because last semester his books ran a little over $500. He said something about books coming with an additional access code which the professors recommend you get so that you have online homework, pretests, etc…
I recommended he consider renting and he is going to look into it but for example Chegg does not support the Pierson (sp) book company that he needs for his physics class.

Honestly I don’t even know what I’m talking about. He’s going to wait till he gets to classes on Monday and ask around in case there are thrifty folks who’ve figured out a way to do this for less.
I guess my question is this: are books really that expensive? He’s the last of 4 and it’s been more than a few year since I’ve had one in school. I recall the older kids mostly renting which seemed to save a little.

I can check the data at home, but I think my D’s books and supplies hit over $900 one semester. I think an Arduino platform was the outlier that semester.

Bad memory - average of $550 per semester, ranging from $438 to $702.

2nd semester Freshman year was the $438 low.

She purchased a few used books a few semesters - you need to get to the bookstore early before they’re gone. Many did come with electronic codes for online access to additional material, homework, etc. - just part of the cost.