I'm sure it will be i think those prices are all placeholders - in another post i tihnk in the modding section i made a quick mod with rebalanced prices which makes most things reasonable
a good idea, but I'd see a problem. you see, given that the number of upgrades is hard limited, you would want to prefer the more expensive upgrades instead of the cheaper, weaker ones. thus, you could keep the upgrade costs constant (maybe increase them with levels), but tweak the effects. for the current price, a 1,5 or so credit boost per level could be ok, after all it should be more expensive (per credit) than mere trade ports, because of the protection and flexibility. likewise, the squadron hangar need not necessarily become cheaper, but could house more fighters. and so on ...
at least I think that would be a better of creating balance, as the upgrades are only comparable on a relative cost-benefit ration, but on a cost basis also.