When at a full stop, the speedo jumps between 15 and 30 mph. Once the car starts rolling, even if in neutral, it'll even out and hover around 20 mph. It works once in a blue moon.

I was going to try to re-solder the board first. If that doesn't work, get a circuit board and try to get it repaired. If worse comes to absolute worse, I might just look for one that has mileage that's close (even if its around 175k).