~ The Lost Tales Volume 1 ~
George Allen & Unwin printed 9,000 copies of Lost Tales 1, and sent 4,000 (unbound) to Houghton Mifflin Company in the USA.  The rarest volume of the HoME series is a HMCo bound -printed in Great Britain- copy of this book.
According to Tolkien: A Descriptive Bibliography, when HMCo ordered 4,000 copies from GA&U, they (rather drastically) underestimated demand.  By December 1983 over 18,500 had been pre-ordered, so HMCo ordered a domestic printing of 30,000 copies.  The US edition was released in February 1984.
The imported text copies have no letters preceding the number line, and the statement "Printed in Great Britain" above it.  These contain all the errors of the UK first printing, except for the offset number in the table of contents.  Due to its scarcity, and the general public not necessarily knowing what they have, there isn't really a trackable "going market rate", but I'd value it about even with its British counterpart.  Obviously, HMCo didn't bother ordering any sheets from GB for the rest of The History of Middle-Earth series.

US printed first impressions have the letter "S" preceding a full numberline, with the statement "Printed in The United States of America" above it.  Four of the 14 minor errors in the British first printing as described in A Descriptive Bib. (p. 247) are found in domestic printings (and remain through at least the third printing).  These first printings, in collectible condition, have a going market rate of $70-$100.
All US first impression jackets were priced at $14.95.
More obfuscations :
Circa 2004, printings were again issued with complete 10-1 number lines, preceded by three letters (QWF).  They are still first editions, same ISBN, and in full cloth - but there were dozens of earlier printings of each title.  Their jackets are priced at $30.
There has never been a second edition, but there have been several variants of the first edition, and again, all with the same ISBN.  BOMC sold full size cloth covered copies (bound by HMCo) in unpriced jackets for a short time, and produced typical paper over boards BCEs thereafter.  Books nearly identical to the BCE but with the title stamped in green or gold on the spine were widely available in book stores and online for many years.  All discount copies state "First American Edition" on the title page:  none has a number line or a priced jacket.  Not all book sellers know one from another, so a lot of five dollar books are wildly incorrectly priced - IMO.
A final notes :
Trade editions of several titles in the History of Middle-Earth series, late printings with jackets priced at $30, have been found in paper covered boards.  I have not heard that either volume of The Book of Lost Tales was ever found numbered and priced and in paper, but... it would seem the age of cloth is truly over, all hail the Kindle.  (Update : only The Peoples of Middle-Earth is still available in hardcover from HMHCo, paper over boards, all others currently out of print.).
The take away from all that: a cloth hardcover in collectible condition is now worth at least $30, and will appreciate in value from here out.  Any other hardcover will likely be available in every used book outlet in town every day for the next twenty years selling for about the price of a sandwich.
book photo book photo
These are the covers of BCE and discount editions.  The books are smaller, and the color of the Tolkien logo is
more yellow or very yellow - they are hard to tell apart from a trade edition just from a photo.
book photo
This is a Book Club Edition (BOMC) - it is easily identified as such.
book photo
This discount edition sold in retail stores for about half of trade RRP.  The jackets are not priced, there is no
numberline, and it does not anywhere identify as anything else but a first american edition.
book photo
Copyright page and table of contents in the BCE and discount editions.
book photo
Copyright page of a US printed first Trade Edition.
Every time I do an in-depth investigation into an edition such as this, multiple copies are purchased for the purpose.
If you're in the market for this title, you'll find some at the bookshop right now.
~ Thank you for visiting ~