The most common and most likely answer to this crossword clue is the 8 letter word BROCADES
B
R
O
C
A
D
E
S
Buddy explains!

The straight part
We know that "expensive fabrics" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case expensive fabrics = brocades.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 BROCADES mean?
BROCADES noun- A thick heavy fabric into which raised patterns have been woven, originally in gold and silver; more recently any cloth incorporating raised, woven patterns.
- An item decorated with brocade.
- Any of several species of noctuid moths such as some species in the genera Calophasia and Hadena
- (metaphoric) A decorative pattern.
- To decorate fabric with raised woven patterns.