WELCOME ABOARD!
This question gets asked on average once every three to four months.
DRM was removed more than two years ago. You only have to be online long enough to register the game. You don't have to be online to play it. Bugs are worked out and gone thanks to hard-working and brillian modders. System requirements are a problem, but unless you're running a very old single-core 32-bit system like mine, you should be okay.
I bought mine on Amazon for $5. For that price you can easily afford to find out for yourself.