Stingy value is thick (5-3)

I believe the answer is:

close-set

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'thick' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?

I don't understand the remainder of the clue.

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(Other definitions for close-set that I've seen before include "(Eg of eyes) very near to each other" , "Tight together" , "With little space between them, eyes perhaps" .)

I've seen this clue in The Times and The Sunday Times.

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