People generally undercut numbers of games still available.

If you good at doing basic statistical probability, and use the same rough model per say that Mr. Pinball does in averaging losses of machines via age per year you can come up with a reasonable number of machines left.

However, I will do a much simpler model for estimation, that does not require formulas.

Star Gazer had a Stern production run estimated at 869 in 1980.
That was 36 years ago.
Since the game was solid state and not an EM, which is important because it was past the time of the "Great Pinball Scourge" of destruction up through the 1970s. This increases the number of potential games left, and not have to be separately calculated. This would have been especially true if it had been an EM during the transition phase.

Now applying reductions due to use, being played out, parted out, and being accidentally destroyed over the course of time, on a yearly basis loss of say 1% per year or roughly 9 machines, after 36 years, that equates to at least 324 machines already destroyed.
(I am not going to consider 2017 yet)

This leaves 545 games remaining.
However, this does not consider games that were placed in storage, are incomplete, missing parts, or backglasses.
That makes it tough to actually restore a game properly.
Considering the age of the machine, you can lop of at least another 30%, which is fairly common based on operators.
That reduces the number of games by another 163.

Leaving the total number of games existing 382/869 at the present time or 44% of the game's original production remaining at the present time.

Granted, this does not mean the games are working or even in quality condition, just "out in the wild".
Hell, they could be in barn loft, or a person's secret torture dungeon for all I know.
Somebody might like the game so much they are hoarding multiple examples in stacks.
This does not also not consider games that were created from parts, playfields, and back glass, which has already occurred.