Growing a Fortune

While getting our retirement account records updated, I discovered that some of the money my wife had in a 401k from a previous employer was in a target date fund.   I like the concept of target date funds.  They adjust automatically the stock/bond mix as they get closer to the target date, usually a date close to retirement. Turns out the nifty fund my wife's little stash was in had a not-so-nifty 0.36% expense ratio. I hunted through the available alternatives  and found a total bond fund, a S&P 500 fund, and a Russell 2000 Value fund, all by Vanguard.  The expense ratios on these funds were 0.05%, 0.04%, and 0.07% respectively.   I then looked up the stock/bond mix in the retirement date fund and approximately replicated the mix using the three cheaper funds.  In about a year, I'll log back in, and rebalance to the new mix of the retirement date fund and repeat each year until I croak or we deplete the account. How much money did I save my ...