How Much Would YOU Guess These 30 Great Books Are Worth?" - Little Leather Library (The Mentor, April 1922)
The pattern
This still is filed under Price-anchoring offer.
Define
A higher reference number is shown first so the real price reads as a concession, not as a starting bid.
Mechanism
People judge a price against the first number they see. The anchor must be a real comparison or it collapses.
Verdict
We have a credible reference the buyer will accept
Why it works
The ad makes the reader set the price before it discloses one. By asking for a guess and printing 884 other people's guesses as a table, it anchors value high using third-party numbers rather than the advertiser's own claim, and the line that not a single person estimated correctly primes the reader to expect a surprise in the reader's favour. The instruction to write your guess in the margin is a physical commitment device - once a number is on the page, the $2.98 in the coupon is experienced as a discovery rather than an assertion. The evidence panel is doing the job a testimonial would do, but as a distribution rather than a quote, which is much harder to dismiss as cherry-picked, and the offer to let anyone inspect the signed originals costs nothing while sounding like an audit. Finally, the price is deliberately hidden in the coupon, so the reader has to reach the ask to learn it.
Steal this when
Your price is dramatically below what the market assumes, and stating it up front would read as a trick or a downgrade. Run a real survey of what people guess it costs, print the distribution, ask the reader to commit to a number, and disclose your price only at the order mechanism.