Torin, catalog for US has always been about 2x, double face for new issues. Your 20 stamp sheets will fit into a smaller container since they are not as large as the regular size 50 stamp panes.
a plate block of 4 might be better financially?
I don't look at new issues financially and any pane of 20 stamps is a new issue for this purpose. However, I really don't see plate blocks of 4 trading much as compared to the full sheet of 20 when the images are the same. I think, as in my guess, that with the many multi design 20 stamps panes, just having a block of 4 from a 20-same pane breaks the flow. So I think most folks would want the full 20 pane.
Now as to what to do financially, only get forever stamps as they increase in value every time postage rates increase.
Even the current $5 and greater face value stamps may take a long time, read a decade or more, to begin normally selling for much over face such that they can be sold over face. Plus if there were expenses, shipping or sales tax that means you need to sell at an even higher price to break even. What will be worth much more later are the $5 and over denomination properly used on cover in the correct time period. Next are the over $5 stamps clean used with a proper contemporary use dated cancel. This does not mean a $10.35 express eagle postmarked 2022. Those items are scarce.