Biggest issue with ostheer teching costs is they were put into place before western fronts came out and were intended for the soviet/ostheer match up to increase infantry battles (As stated in their balance notes at the time it went live). Now that OKW and USF are here its a completely different story since both those factions can bring armor on much faster.
OKW and USF tiering prices are simply off.
They were made with OKW and USF in mind, not soviets and ost, they had made an effort to make teching slower for vanila factions and then released new armies with turbo teching.
Both WFA armies teching is simply too cheap, because decreasing teching costs for vanila armies will only shorten early and mid game, making light armor even more irrelevant then it already is.