With ETFs, you can buy just one share if you like, there's no minimum investment unless for some reason the brokerage has imposed one. You should check at http://www.savingforcollege.com/coverde ... providers/
. But the ETFs by themselves do not carry a fixed fee.
I looked up these ETFs (you can do a simple Google search to find them) and it appears that their only expenses are the management expense ratio, which is a percentage, not a flat fee. It just acts as a small drag on growth.
The place where you usually find minimum balance fees is mutual funds, not ETFs.