
Here's a table with trade routes' estimated profitability. Higher number (greener) is better. Buy in the city from the first column, sell in those from the first row.
It takes into account differences between "Supplies" and "Looking for" goods. v0.66.4 and any future version supported as long as city goods preferences aren't modified.
I can update it with just a few copy-pastes though—as long as text phrasing doesn't change too much. Although it should be simple enough to adapt a few text input formulas to different phrasings.
There's a table with the actual goods a few comments below.
Edit: I realized I forgot to consider differences between "Looking for". Pseudo-formula is: ( S1 <> S2 ) + ( L1 <> L2 ) + ( S1 = L2 )