A fully restored Creature with all new ramps, hardware, plastics, playfield, new coin door, and rebuilt cabinet fetches around 8k.

Yours looks nice, but based on the wear marks by your coin door has seen considerable play. Another issue is the credit dot, I'm sure it's something minor like the ball not passing through the bowl in a while, but would be good to clear up the cause. Last thing, and most importantly for this title... how green is the hologram? Is it original or a reproduction?

I'd take some close ups of the playfield, shooter lane, boards in the backbox (especially near the batteries), and the hologram when lit. The translite is also hard to find in nice shape, I'd take a picture of the back of it. If it's nice that also adds substantial value.

Thirding the 4-6k estimate