I think there are two meaning of "ㄹ테니" 1. Because + will 제품의 질보다는 값이 중요할 테니 = Because price will be more important than product quality~~ ex) 오늘 밤 비가 올테니, 우산을 가져가. Because it will rain tonight, take an umbrella. 2. Because + should (indicate what is probable not obligation) 제품의 질보다는 값이 중요할 테니 = Because price should be more important than product quality~~ ex) 그는 지금은 바쁠 테니 1시간 있다가 전화해봐. = Because he should be busy now, call him 1 hour later!