A perception of value depends on an assessment, which requires information. Suppose the thing you thought would provide $1 of value doesn't actually.

Edit: concrete example. https://en.wikipedia.org/wiki/Lemon_(automobile)

Edit2: metaphorical example. I have a very valuable bridge to sell you. Just hope the value you receive isn't different than the value you perceive at transaction time. https://en.wiktionary.org/wiki/I_have_a_bridge_to_sell_you