Thanks! These are exactly what I was looking for! Now I can see, for example, that the lowest upgradeable UA fare BUF-FLR is 700+, as opposed to AA's 401.00. If we're going to switch airlines so as to not have to connect through ORD, we need to know what we're into.

Aside: 'let me ask...again' refers to the fact that a moderator closed my original query thread without reading that I wanted FARE by booking class, not availability.