I completely agree. If you have a decent space to record in (i.e. very little outside noise), and spend the money on half decent equipment, there is really no need to use an expensive studio to record a cd anymore. One thing I have found to be a pain though is trying to adjust the gain when I'm recording myself (that old inability to be in two places at once. Someday somebody will fix that...)
For mastering however it is probably worthwhile to use a professional mastering studio. They tend to have a lot of very expensive gear that isn't worth buying for a home studio, as well as extensive experience which allows them to give the recording the best final polish possible.