There's a stack of drug books in our med room, and there's always a recent (within the last year) edition there. You can always count on a new grad to have a book in the room
Glad I didn't bother buying a new one. Would have been a waste, as every time I need the info, it's there. AND, if I still have a question, I walk two steps to the phone, dial Pharmacy, and ask. They answer either immediately or in a minute.
By the way, my edition became "old" before I graduated as well, and didn't get a new one then. Nothing was really outdated! And when I started work, I saw the stack of books and realized I had saved myself some bucks. I suggest you do the same before buying new.