i think vegas is what my lecturers like to call "top end consumer" video editing software, and if im correct its Editing and post production in 1 package, Its a great peice of software and as you can see kevlar has used it to great effect to create those
TG intro titles. The difference from the adobe package, in the the eyes of my lectures, is that the adobe package is a "low budget professional" package and its also 2 peices of software rather than just the one.
Anyway asch there are a number of places to get great deals on both of these powerfull video editing softwares.
The thing you should probably think about is how often are you likely to use it?
i have adobe because thats what my university use and i use it quite alot.