What kind of trouble?

"Yes, the top-grade Foundation Building pill." The woman said, intentionally pointing out the two words "top-grade".

Feng Jiu smiled when she heard this. Ordinary Foundation Building pills should be common staples in the upper mainland's influential clans. However, the top-grade Building Foundation pills had very few impurities, so they were very rare and precious. Ordinary alchemists could only refine one top-grade Foundation Building pill every one hundred Foundation Building pills. Therefore, although this mirror was a magic weapon, it was not worth bartering with a top-grade Foundation Building pill.

"Eh? It needs a top-grade Foundation Building pill?!" She said with some regrets. After touching the mirror, she had to hand it back. "I have no top grade, I have only one inferior one." 

The woman smiled. She took back the mirror without saying anything. It seemed that she wasn't surprised at all.