Well for instance the Total Stock Market Fund (VTSMX) states this for the sub 10k account -
For nonretirement accounts, traditional IRAs, Roth IRAs, UGMAs/UTMAs, SEP-IRAs, and education savings accounts (ESAs):
We charge a $20 annual account service fee for each Vanguard fund with a balance of less than $10,000 in an account. This fee doesn’t apply if you sign up for account access on Vanguard.com and choose electronic delivery of statements, confirmations, and Vanguard fund reports and prospectuses. This fee also doesn’t apply to members of Flagship®, Voyager Select®, and Voyager Services®.
Eliminate this fee by registering for our convenient e-delivery package.
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Given that you can switch now then after you hit >$10k transfer to the admiral shares (VTSAX) which are available at more than $10k.
Of course you could do that with any fund that strikes your fancy as long as you meet the $ requirement.