Some Gottlieb Speech board observations - The SC-01 speech chip is up to $35 if you can find them and the LM379S audio amplifier that is usually blown up because of power supply board failure runs $10.
The same power supply failure usually takes out some interface ttl chips (and the socketed 74LS373 on the Q*bert main board as well). Some other miscellaneous chips prone to failure are the 1408 dacs ($3 to $5) and the RIOT 40 pin chip ($7 to $10).
So if you buy or trade for a used non-working one and have it repaired, those are some worst case parts costs to consider.
Given that, $125 total (non-working board plus repair cost and shipping both ways) to have one repaired or to buy a repaired and / or tested and working board is not that bad of a deal. BUT - be sure your power supply board has been rebuilt and upgraded before you plug in that nice working speech board that you just paid all that money for.
Bill