Not sure what that has to do with Jail-breaking. I'm pretty sure you can download and install random apps on a non-jailbroken Android phone. Me, I only use the official Market Place App store to get my apps, even though my phone is rooted. And I only used well vetted rooting techniques to root (i.e. Unrevoked).

I didn't root to save money on apps - I rooted so I could remove the bloatware.