to make sure that you speak with someone who is very knowledgeable about the prices of certain things.

一定要跟某些很了解价格行情的人谈谈。

关于购买艺术品 - SpeakingMax英语口语达人

But I'm not sure that you can really make that assumption based on something that someone creates

但我不确定你真的能基于某人创作的某些作品来做那样的推断，

印象深刻的展示会 - SpeakingMax英语口语达人