You have 20 Common App spots. Don’t be afraid to use them.
OSU will likely be cheaper than Pitt but you had Pitt on there for “family” reasons. So no reason to remove any - unless you run out of spots. This makes it more difficult - i.e. you drag the decision even later and it gets torturous - but at least you’ll have a chance to go visit (you can wait until after offers) and see if one is better than the other - or worth spending more on.
btw - can’t say it’s true today but two years ago, if you did the Pitt online session, you got an app fee waiver (was Hail2Pitt) - so you might see if that’s still a possibility - save you the $60 or so.
Good luck.