Value of cards per Square Inch/Foot vs Real Estate

[brunswickreeves]

A recent post evaluated the choice between million dollar real estate and a similarly priced pre-war card.

When thinking about real estate as a value per square foot, I wonder the comparison of Authentic (common baseline) graded cards. Which cards have the greatest value per square inch, and what does that translate into value per square foot based on recent Authentic graded sales? Aside from the obvious T206 titan outliers (Wagner, Plank and Doyle error), what are some other examples (Ruth, Cobb, Mick, etc.) from pre and post war?

Not a post on merits of a card or preferences, but a different data-driven way to assess value, or what may be undervalued/a good buy. Pre-war example below. Add your favs!

1910 Tip Top Bread Wagner (1 13/16 x 2 3/8), PSA Authentic for $30,000
=4.304 in^2 => 0.0298 ft^2 => $30,000/0.0298 = $1.006MM per sq ft