I am all about getting the best software for the cheapest price, nothing wrong with bargain hunting. I bought Sony Movie Studio Platinum 9 for only around $35 off Ebay. As already mentioned, new software is always coming out, so the more obsolete the previous versions become, & the cheaper they get. So I look forward to seeing the 1st versions of Adobe Premier or Afetr Effects drop down to just a hundred bucks or two in 5-10 years, I'd buy it!
& sometimes it's hard to forget to mention other GREAT free programs to use in conjunction with Sony Vegas.
A great free sound program Ive used & got good with is Audacity, & is ideal if you want to do comlicated sound fx, music editing, etc that otherwise cant be handled in Vegas.
For still image, multiple layer/matte elements & effects creation & composting, the free alternative to Photoshop such as Gimp is perfect, & has served me well. I reaaly dont see myself needing to get Photoshop anytime soon, if ever.
DVD Shrink for ripping your DVDs.
So dont expect to be able to rely on just one magic program to do it all for you. (Unless you can afford such an expensive program). Expand your tool box with as much as you can so you can be as creative as you can.