To all upper year ChemBio students, what are the textbooks that are absolutely necessary (those contain access code if any) for ChemBio II courses, and how much did you spend approximately on textbooks in total for level II? Thanks in advance

None are absolutely necessary - though they might have added access codes into some since I took those courses. But even so, with access codes there is usually an alternative to that. In science in general, I'd argue that the vast majority of textbooks are not necessary, though if you find you learn well from textbooks, you might find them helpful.
Personally throughout two degrees, I have saved thousands of dollars by just going to class and learning the material then, rather than later through a textbook.