Based on the $10,000 number I assume you are looking at Vanguard index fund ADMIRAL shares. Simple solutions.
1. Use a Vanguard target retirement fund. Minimum is 1,000, and it is made up of the big total market index funds all in one fund.
2. Build a portfolio with ETFs. All the big index funds that are avialable as admiral shares with 10k minimums are also available as ETFs. With ETFs you only have to have enough to buy 1 share which is normally in the $50-150 range.
Here is a cheat sheet:
VTSAX = VTI
VTIAX = VXUS
VBTLX = BND
VFIAX = VOO
You can actually pull up any Vanguard fund on the website and right under the name in small print look for "Also available as Investor Shares mutual fund and an ETF." The ETF is a link. Find the funds you want, and click the ETF button.