Fair point, though that also should point out the Abrams is a good 3 feet and change longer in the hull and I think wider as well. I'm thinking of 'taking the turret and making it larger' only really involving that amount of extra steel since the composite front end, gun, autoloader, and the hull of the Russian tank would all stay the same. IIRC there's also a lot more armor on the Abrams hull as well compared to the T-72, but I can't name that offhand.
And as far as the T-80 goes, granted, I'll concede the price difference between it and the Abrams is pretty significant, but I don't think it comes down to a case of 'buying 100 2 million dollar tanks or 40 5 million dollar tanks' as far as resource availability. I could be wrong!