I have no price insight, but probably slightly more or roughly the same value as MACH 3 boards. Neat to see an original one; it is just a straight ROM swap from Mach 3. The sound board (separate from the main 3-board stack) is also unique to M3/UvT as it has a line-level input that the LDP makes use of.
I burned & popped this it in my cockpit recently and I have no plans to go back to Mach 3. Cool game that I'd spent no time with until now. I had to re-wire the control panel to make the game work right in M3, but werdly Gott ran an extra unused wire in the harness from the filter board to the CP connector in MACH3, so it wasn't much trouble to add the additional switch line. Maybe they knew...