One of the inconsistencies in Panzer Corp was the cost of upgrades. It was ridiculously cheap to upgrade a Mark II Spitfire to a Mark V or a Panzer IIIF to a Panzer IIIL but this wasn’t carried through consistently. e.g. The Spitfire IX was very different from older versions and a Tempest was different from a Hurricane but if one upgrade is cheap then the name change shouldn’t make the Hawker upgrade more expensive than the Supermarine. Likewise changing a Panzer II battle tank into a Panzer II recon should be cheap. This system penalizes the British as their Tanks were renamed every few iterations but the Germans used the same names throughout.