Forget fees for a moment and take this time to learn who you are as an investor. If you wish to dwell into multiple ETFs as opposed to VOO, go for it. The few dollars on $400 a month is not really going to make much of a difference when you spend more on a cup of coffee at Starbucks. Overall I feel that the transactional fees are anything but minute compared to the experience and education you get in your journey to understand what kind of investor you are going to be in years to come. Most people really figure out what kind of investor they are after the 10-year mark. It took me 10 years to understand what kind of investor I am, and I am able to figure out what kind of risk I am willing to take because I have experienced 5-6 crashes in my holdings over that time period. To be deterred by the few dollars when you can simply top up the difference from your monthly income is just not worth your time unless you are pumping in $10,000 a month consistently. Or if your average trades exceeds 5 figures per trade. Stop saving pennies, look at the big picture. If you feel you want to take the journey down investing across a broad range of risker assets, go for it. Just understand that you might hit a few walls and expect to make mistakes. Everyone thinks that they are high-risk investors until they see their holdings drop by 75%. In the longer term, the index is hard to beat. But it is not unbeatable in the short term. But understand to carefully differentiate the difference between skill and plain luck. Whom most of us simply are: lucky.