The most common and most likely answer to this crossword clue is the 8 letter word AUCTIONS
I've seen this crossword clue in The Times
A
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More clues leading to the result AUCTIONS
Buddy explains!

The straight part
We know that "Sales" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sales = auctions.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does AUCTIONS mean?
AUCTIONS noun- A public event where goods or property are sold to the highest bidder.
- The first stage of a deal, in which players bid to determine the final contract.
- To sell at an auction.