Timothy, I would say that you have to shop carefully to find good “pre-owned” instruments. I have never seen a high-quality non-wooden instrument anywhere, and the only Yamahas I have ever seen are the student Yamahas that are given to grade-school children.
Plastic recorders are definitely NOT only for children. Many professional players use plastic instruments for practice, because they don’t require maintenance and can be played for hours and everybody says that a good plastic recorder is better than a cheap wooden one.
Buying a second hand recorder may be dangerous if you’re not expert enough to check its conditions.