CraigsList is just the local newspaper "for sale" ads gone electronic. Just like a newspaper ad, people tend to amplify the good features, while overlooking flaws in their wording so it is "buyer beware", or at least "buyer be wary". I would never buy critical, machined components sight unseen from an individual. You simply have no protection from misrepresentation, or misunderstandings. Even buying used stuff from someone you know can carry risks.