After many new games I have played and seen, I must say that there are definitely some units which are too expensive and/or overpowered.
Battleships and cruisers are so rarely bought that it is ridiculous.
Tacs, even tanks (except Germany mainly), and AA guns too to some measure.
I am pleading to the creators of the game to make those units more balanced for the next AA game, or the upgrade of this one.
Inf, art, mech, figs, boms and minor ICs are bought very often.
Major ICs should maybe be a little cheaper.
Harbours and airfields are more or less ok.
Cheers :)