Total costs may include various fees (purchase, redemption, auditing) and other expenses.
Not included in the total expense ratio are transaction costs as a result of trading of the fund's assets.
In general it seems that there is, at best, a positive correlation between the fees charged by a fund and the returns it provides to investors.
[3] Once an investor has decided on a mix of assets (asset allocation) that suits their situation, needs, and goals, they need to know whether to invest through (more expensive) actively managed funds, cheaper ETFs (exchange traded funds), or directly.
Professional financial advisers who have a fiduciary duty towards their clients can help with determining the best trade-off between all of the different investment options available, looking at all of the characteristics, including the total expense ratio.