well informed
adjective uk/ˌwel ɪnˈfɔːmd/ us/ˌwel ɪnˈfɔːrmd/
C1 （对某一话题或总体情况）非常熟悉的;消息灵通的
having a lot of knowledge or information about a particular subject or things in general
He was well informed and shrewd, with good, calm judgment. 他见多识广，精明能干且有着出色、冷静的判断力。
How well informed is the customer about the range, quality, and cost of the products on offer? 顾客对现有商品的范围、质量和成本了解有多少呢？