If someone likes a tune and feels is worth whatever then that's their decision. The value of a record is relative to how much a person wants/likes it.
What I don't understand is people who buy records just because they are rare. Sometimes without even knowing what they sound like. What's the point in having a record as some sort of trophy??
I think certain people just look out for when someone says a tune is good/rare then buy it blindly so they can show off.