I think we should put "no valuation questions" in FAQ because they're purely opinion-based. The value is specific to the seller and the buyer, and at best local to the time and place that the buyer or seller is in.
I think it would be better to address them explicitly in the FAQ in the hope of having to close fewer of them.
How much is a Trek Alpha aluminium 58cm road bike worth?
How much is a mass production aluminium road bike frame worth?
How do I tell if a used bike (craigslist) is worth it?
(a lot of "how much worth" search results, in other words)