Moving on from a Saltarelle Le Bouebe

[diatonix]

The total weight of an(y) accordion  (chromatic or even more so: diatonic) doesn't give you all the information you need. It's how this weight is balanced between left and right, which is important! Personally I do not worry too much about the right hand side, while I (and surely most players) appreciate a light-weight bass - after all it's the part og the box which is constantly being moved.
And again, good reeds and good bellows have their say as well, as your left arm has to work less, without the bass-part turning into a heavy brick.