I realized after posting the comment that the way to get a fixed price index fund (where the fee is not tied to the asset size) is just to buy stocks directly. Once you pay the one time commission, you own the stock forever with no yearly management fee.
Of course, that comes with other costs (you have to adjust yourself when the index changes, commission when you sell, etc).
Which index? If it's an S&P500 one that's 500 stocks to buy. What happens when companies enter the S&P500 or exit it? You would need to trade again which means more commission fees.
What if one company in the index grows considerably while another one falls in value? Do you rebalance between those two? More commissions. Index funds hide all of this and I would guess it winds up cheaper particularly if you include effort.
I realized after posting the comment that the way to get a fixed price index fund (where the fee is not tied to the asset size) is just to buy stocks directly. Once you pay the one time commission, you own the stock forever with no yearly management fee.
Of course, that comes with other costs (you have to adjust yourself when the index changes, commission when you sell, etc).