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

The straight part
We know that "Buys" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case buys = acquires.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 ACQUIRES mean?
ACQUIRES verb- To get.
- To gain, usually by one's own exertions; to get as one's own
- To contract.
- To sample signals and convert them into digital values.