Would you pay $100 extra per year to get 69% yearly savings rate?

Our 403b provider is offering us an all-in-one ETF portfolio option for 0.15% expense ratio, compared to the standard options we have which is 1.56% ER. <br><br>I'm planning on saving 8500/month for the next 20 years. If I go with the ETF option, after 20 years, I'd have paid $30,000 in fees and have a total of $3.2 million. With the standard portfolio option, I'd have paid $114,000 in fees and have $2.7 million.<br><br>Is there a catch I'm missing?