Seriously, do what I said in my OP and you'll really get a sense for how many systems there could be. I doubt many will ever even get out of a 1000 star bubble.
I remember doing a similar thing with Frontier: Elite 2. From Sol, I just held the Up and Left keys on the keyboard and kept scrolled. After about 20 minutes, I got bored, so I taped the Up and Left keys down on the keyboard and went out. When I got back at least an hour, maybe more, later, it was still going...