"The market is not big, but small." Is correct.
This reminds me of the English word 'Kitschy'
Meaning (sentimentally) trashy. I think more of kicsi as like 'titchy'.
"The market is not large but small." Why is this response wrong?
It is not, please report it next time.
What's about a little market? (It was wrong)
Well, I wrote market place and it was wrong. Just market. Pffffffff