It's sort of cliche, isn't it?
→   그건좀 뻔하지 않니?

[예문]
A:What do you think about giving my girlfriend a bouquet of roses
   for her birthday?
  여자친구 생일에 장미꽃을 선물하는것은 어떨까?

B:That's it? It's sort of cliche, isn't it?
  그게 다야? 그건 좀 뻔하지 않니?

A: I guess you're right.
 네말이 맞는것 같아.