first off
first off
(informal, especially British English) before anything else
First off, let's see how much it'll cost.
e.g.
You've got the wrong guy. First off, my name's not Sugimoto. 人違いだな 俺は杉元なんて名前じゃねえ (
/yupeco/『ゴールデンカムイ』
16話)