# The Unconquerable by Helen MacInnes — resale value

Source: JunkPal price guide — https://junkpal.ai/products/the-unconquerable-helen-macinnes-ol3923121w

**The Unconquerable by Helen MacInnes** — resale value from real closed eBay sales.

Live listings and the full sold-price history are on the page: https://junkpal.ai/products/the-unconquerable-helen-macinnes-ol3923121w

Values are medians of real closed eBay sales, updated 2026-06-19. They are estimates for reference, not offers or appraisals — condition, completeness and edition move them a lot, so compare against the sold listings before pricing anything.

## Check the market

- [Sold listings on eBay](https://junkpal.ai/api/go?to=https%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_nkw%3DHelen%2520MacInnes%2520The%2520Unconquerable%26LH_Sold%3D1%26LH_Complete%3D1%26mkcid%3D1%26mkrid%3D711-53200-19255-0%26siteid%3D0%26campid%3D5339166094%26toolid%3D10001%26mkevt%3D1%26customid%3Dmd-sold&p=md-sold) — the closed sales these medians are computed from
- [Live listings on eBay](https://junkpal.ai/api/go?to=https%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_nkw%3DHelen%2520MacInnes%2520The%2520Unconquerable%26mkcid%3D1%26mkrid%3D711-53200-19255-0%26siteid%3D0%26campid%3D5339166094%26toolid%3D10001%26mkevt%3D1%26customid%3Dmd-live&p=md-live) — what sellers are asking right now

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## Details

| Field | Value |
| --- | --- |
| UPC / EAN | 9780002218573 |
| Brand | Helen MacInnes |
| Published | 1970 |
| Publisher | ISIS Audio Books |
| Pages | 512 |
| Editions | 9 |
| Category | Thriller |

## The Unconquerable resale value

**The Unconquerable** by Helen MacInnes (1970). Across 9 editions. Used-book value depends heavily on edition (first printing vs. reprint), condition, dust jacket, and whether it's signed. First editions and out-of-print titles command the biggest premiums.

### What drives the price

First editions/first printings, intact dust jackets, signatures, and unmarked pages are the top value drivers. Book-club editions and later reprints are worth far less.

## FAQ

**Is this edition of The Unconquerable rare?**

While it has 9 editions, the 1970 publication date makes it a sought-after classic thriller.

**What is the ISBN for this book?**

The ISBN for this edition is 9780002218573.

**Who is the author of this 512-page thriller?**

The book, The Unconquerable, was written by Helen MacInnes.

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Full price guide: https://junkpal.ai/products/the-unconquerable-helen-macinnes-ol3923121w
How these values are computed: https://junkpal.ai/methodology
Cite as: "JunkPal price guide value as of 2026-06-19, based on real sold listings (junkpal.ai)"