[DJCollector1]

I'd personally go with the Willie Mays for several reasons.
Part of that is I do expect a bit of an uptick in value when he eventually passes.

I'm not really sure why the Brooks Robinson cards don't sell for more than they do.
I'm sure Mark or a few other hardcore Brooks collectors have a few theories. I tend to think he has been so "accessible" to the fans over the years, and signing literally everything tossed his way, that may well have something to do with it.
This is really just a wild guess though.
(though the flip side can also be argued / meaning he was always so good to the fans, his stuff is more popular than other "curmudgeons" so to speak)

Thinking about this deeper, it seems that 3rd base in general is a position where the "greats of the game" generally go a bit underappreciated.....
Boggs, Brett, Robinson, Santo, Schmidt....aren't all these guys cards a bit underappreciated? Or is it just me?
I don't track their prices that well, but I tend to think most all of them can be had at a relative bargain compared to other positions.
Part of this just might be that their rookies and cards in general are "newer" and more heavily produced, (think 70's onward) with the exception of Robinson.