For CHEM 1A03 Titles sells the text, solutions and code for $107. The code alone costs $50 meaning $57 is the price for a new text and solutions. However people are selling the text and solutions for $55-90 used. Are they including the code? I thought the code wasn't reusable...am I right?

Yes, it's not reusable. They're probably not including the code. MasterincChemistry was required during the first term of last year (although not in the second term last year, or now), so it's almost certainly previously activated.

Buy straight from Titles if you want the MasteringChem code too.

Might as well buy new from Titles. I think a lot of the people that are selling their chem textbooks for that price are not factoring in the price that we had to pay for MasteringChem.