I did a quick search of the web and found a "slip sleeve" version for $274.95 from what I would definitely consider a reputable company.
The product listing indicated that the disc did NOT include DVD Architect, but three reviews listed on that site indicated that it did. The big risk is finding out for sure what this "special disc only version" might be missing: does it include the AC3 encoder? DVD Arch (i.e. actually has a serial number for DVD Arch -- doesn't just happen to have the install files on the disc)? etc.
Regarding updates: Usually the Pro upgrades are about $150 (?) for the first month or so after a new version comes out, and after that about $240 (right now) normal upgrade price. You can upgrade from any version to the current version for the same price: could go from Vegas Pro 4 to Vegas Pro 10 for the same price as someone going from Vegs Pro 9 to Vegas Pro 10.
Typically, you can get an upgrade from X to X+1 for free if you bought X from an official Sony reseller less than 30 days before X+1 came out.
[Edit:] Actually, if you click on the photo to enlarge the disc sleeve artwork, it DOES say it includes "Vegas Pro 10, DVD Architect Pro 5.2, and Dolby Digital Professional Encoder". I don't know what's missing? Looks like a great deal.
What is your upgrade price through the SCS website? Check My Account/My Software. On that page you will see all the software registered to you, plus the free updates and the paid upgrades.
Through SCS you know that you will have Vegas Pro + DVD-A and everything will be legit. The other offer may be legit too, but check carefully before you buy.
Thanks for the information, guys. I ordered it from Amazon coming from Adorama Camera. They assured me if it didn't have a S/N that I would be able to return it (by raising a little stink). So in a few days I should be a pro user. What little I had used Pro it seemed very nice.
VMS and DVD-A Studio are great products. I found them to be feature rich and stable. Plus everything you learned in the Studio versions will be applicable to the Pro versions!