final cut studio upgrading help

I recently decided to buy Final Cut Studio and decided that since I didn't needColor I would save a little money and buy FCS 1 instead of 2, so I bought it on eBay. But I didn't look closely enough at the listing and ended up with "Upgrade from Production Suite." But finding an old copy of this for something reasonable has been hard.

What I would like to know is what this product can upgrade from specifically. Basically, I'm looking to buy a serial, with an older product so that I can implement the software I already have. The product number is M9913Z/A. Could I install this using and older version of Final Cut Pro, and not the Suite? I see there is another product that is M9912Z/A listed as "Upgrade from Final Cut Pro."

I saw another listing on eBay for M9913Z/A described as "Upgrade from Final Cut Pro." Is this person simply mistaken, or is there no real distinction between these two products?

Was there a price difference when Apple was selling these? Does anyone know how specific the serial recognition is, or what the authorization process consists of?

Thanks a lot in advance.