Between us, my hunting pards and I have owned more than a dozen 700's, from 1963 to 2003. Over that 40 year span, there have been lots of detail changes in the model...from little stuff like buttplates and grip caps, to steel formulas and trigger group/safety configurations. All of our guns were bought new or as-new, and after careful examination.
I don't advocate buying on internet sites, sight unseen. You have to learn what to look for, and see for yourself. This may mean a trip to the ONE good stocking gun store in your state. But it's worth it. And if your careful exam misses something that crops up later, the store had better be one that will help make it right. We have never had a bum 700. Most have been superb shooters. And when one was sold or traded, the next owner got a bargain. Try to be that 'next owner'!!! Good luck!