I'm thinking that most of the repro playfield sold are based on speculation to find the game, making money in selling them at a higher price later or to make a new machine.
I'm also in vidz hobby and lot of repro parts for rare games are going for a complete repro game. (Major Havoc, Quantum etc ...)
I watched pictures from all Star Gazer possible and most already have nice playfield, no need replacement.
It's easy to find pictures from trashed Fathom, EBD or Flash Gordon playfield but much harder to find trashed Star Gazer playfield.
It's also better to try to keep the original playfield the most possible for a rare and nice game this kind in my opinion.
I stick to my speculation 125 to 150 still available. Project, complete or still undiscovered !
I think it's a big number for a 37 years old game that wasn't very popular back in the early 80's.
Not sure all operators kept them for all that time, lot of them were trashed or destroyed by poor storage.