*If somebody is smarter than me and thinks this is a stupid idea, call me out on it. Always willing to learn more.
Ok, good...time to put on your learnin' hat.
If by "investor shares currently trade around half the cost of VTSAX" you're referring to the share price (or Net Asset Value), you need to stop caring about that. Share price is an entirely irrelevant piece of information when comparing investments. Its only use is to compare the current market value
of a single investment to its value sometime in the past (and even then it's not very useful).
If you instead just mean that "you pay less to get $1 of divdends from VGSLX than to get $1 of dividends from VTSAX", then sure, that's true, but the common way of expressing this is via their dividend yields. VGSLX currently "yields" 3.19%, while VTSAX yields 1.79%.
But most importantly, dividends aren't a sensible way to measure your "success", particularly for a 24-year-old who has absolutely no need for dividends. When a fund pays you dividends, they are hurting their share price. Dividends don't actually make you money (and they explicitly cost you money if held in a taxable account).
For visual evidence, see the two charts below. The first shows the 10 year price chart for the REIT fund (blue line) vs. the Total Stock Market fund (orange line). Stocks beat the REIT by almost 30%. But that's because the price chart ignores dividends. In the total return chart, which includes dividend reinvestment, the situation is flipped, with the REIT slightly beating Total Stock. If the REIT had held onto its dividends rather than paying them out (which is not actually legal for a REIT), then its price would be higher today and the price comparison would look similar to the total return comparison.
REIT vs. Stock Market, Price ChartREIT vs. Stock Market, Total Return ChartIt's ok to put some money in REIT investments, but the dividend income is *not* a rational reason for doing so.