Home recording has got to a point wwhere you can indeed create a pro sounding project without having to spend all your time in a studio. As mentioned above, it's often the expertise of the engineer you're paying for when in a real studio, but with enough experience of your own (or that of a musically inclined friend, as was the case with most of the recordings I've been part of), you can do well at home.

It does also depend on the quality of the gear you have at your disposal. For example, my old band recorded two albums with a home setup, using pro monitors and mics, rack effects, a good desk, a souped-up Mac Pro for tracking onto with Logic (we previously used Cubase and Ableton Live), a MacBook Pro for testing ideas out and so on. The outcome was really cool.

What really lifted it all though was a professional mastering job. We got a pro mastering job done from a pro guy in Germany, and seriously, that made all the difference.