Faltering trade, piece lower in value (10)

I believe the answer is:

depreciate

I'm a little stuck... Click here to teach me more about this clue!

'lower in value' is the definition.
'depreciate' can be an answer for 'lower' (thesaurus). I'm not sure about the 'in value' bit.

'faltering trade piece' is the wordplay.
'faltering' is an anagram indicator.
'trade'+'piece'='tradepiece'
'tradepiece' is an anagram of 'DEPRECIATE'.

Can you help me to learn more?

(Other definitions for depreciate that I've seen before include "Lose value with time" , "Belittle; lose value" , "Gradually lose value" .)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.