i'm pritty sure any save data will be stored on your computer and not on the dvd-rom, since it's probably not rewritable... o.o
I'm also pritty sure there is a refference on the box to the system requirements... and some note that you need to have a steam account and launcher to play it.
If you can't find the system requirements + basic info here is the link:
https://support.frontier.co.uk/kb/faq.php?id=292
In these modern times I even doubt you ever need the DVD-Rom except for the installation of the game, even then you could opt to download on steam when you redeem the code that's inside the box.
It's more used as a collectors item, since there were manny updates after they released the DVD's you probably have to download ALOT anyway after installing.
Steam also provides cloud save for games, so keep in mind to check those settings, mine are off since i don't like the sync everytime I close a game and the duplicate save errors -.-
Anyway it's a personal choice.