Welcome, be careful. I bought my first one 18 months ago. I've got twenty something now.
Occasionally one pops up for sale here, but not often. Aussie Arcade is a good place to find them for sale, beware getting to involved there in the forums though.
There's a couple of facebook groups, pinball oz wide and australian pinball buy and sell that are pretty genuine and have lots advertised. as said since covid prices have risen sharply and lots of people are trying to cash in on it.
Not sure if they'll fall all the way back again, i suspect not.
Why Star Trek, is it theme or have you played it and fallen for it?