Like Mike said

As a user of both Movie Studio and Sony Vegas Pro I agree with Mike completely. Studio has many of the features of Vegas Pro, especially at the functional level. In other words, you can do some pretty sophisticated editing in Studio, you just won't find bells and whistles such as wave form monitors and the like, and there is a limit (more than most will ever need) on the number of tracks that can be used.

Our shop uses Studio for light jobs, Vegas Pro for more complex work. The price is right for Studio and, as Mike points out, you can upgrade to Vegas Pro relatively inexpensively in the future.