That's a nice breakdown there OP.
A couple of months ago, or maybe even just one month ago, I would've said Sano. Now I'm not so sure. You can cite small sample size all you want, but so far in 43 games at Double A Baez has already passed Sano's HR mark and is tied with him for XBH despite arriving a bit later than him. 30 XBH in 43 games as a 20 year old in Double A is kind of eye opening. Sano got real hot for a minute though too in Double A, but then cooled off pretty quickly. I wonder how much of Baez's performance is sustainable considering his strikeout rate and what exactly he is going to look like when he hits a rough stretch again.
It sounds like Sano has a chance to be a quality defender at third, but Baez could be that as well, while still offering a legitimate chance to play an adequate shortstop possibly. I think I would have to chose Baez at this point, and disagree with the rather pronounced price disparity.