Rayvt; “Their database seemed to be really really good, totally free of survivorship bias. But $2400/year is a lot.”
Ray your obviously an astute long-term investor. Seems like I remember back near the turn of the century you posted about spending several hours a day on the subject. Retired early around 2006 mostly from investments.
In all likelihood your portfolio has increased significantly in the last 20 years as by my reckoning you will always live below your means. My point is that perhaps you may just be a little penny wise and pound foolish.
With even a 500K investment if the ultimate version could increase your investment income by only 0.5% it would pay for itself. I wouldn’t make a bet that most people would come out ahead using p123 but I’m pretty convinced you would.

But then again perhaps I’m just an impulsive risk taker.