ECON for Macro, 2nd Edition, by McEachern. The new version comes with the Aplia code (which separately costs $60), and the book is only $75 or so in the bookstore. This is one of those rare cases where I actually recommend students wait and buy the book new in the bookstore.
ECON for Micro, 2nd edition, by McEachern. Same rules as with the 205 book. Buy it in the bookstore in January.
Macroeconomics, by Mankiw. The 7th edition is the most recent version, but it’s also very expensive. Not much has changed since I last used this book, when it was still on the 5th edition. If you can find a much cheaper 6th or 5th edition online, go ahead and use it and save yourself at least fifty bucks.
Managerial Economics and Business Strategy, by Baye. The 7th edition is the most recent version, but like Mankiw, it’s also very expensive. Far too little has changed even from the 5th edition for me to recommend buying the 7th. Go online and get a 5th or 6th edition. You can probably get one for less than $20. It’s a good book, one that many students have told me they kept and never sold back, so buy it, read it, and keep it.