Keep in mind it was NOT an all or nothing proposition for using the Shuttle. We launched satellites while the shuttle was running using Titan, Atlas, and Delta

Keep in mind it was NOT an all or nothing proposition for using the Shuttle. We launched satellites while the shuttle was running using Titan, Atlas, and Delta rockets. I would imagine if it was more cost efficient to use those rockets, they would have done so. https://en.wikipedia.org/wiki/List_of_Titan_launches https://en.wikipedia.org/wiki/List_of_Titan_launches and https://en.wikipedia.org/wiki/Delta_IV https://en.wikipedia.org/wiki/Delta_IV and https://en.wikipedia.org/wiki/Atlas_V https://en.wikipedia.org/wiki/Atlas_V