Today a typical siren setup for a locality costs roughly $20,000 per siren. During the Cold War most sirens were purchased via Civil Defense funds.
They weren't paid for completely with civil defense funds they were paid for with "matching funds". CD paid for half.
The Feb 1, 1979 Federal Price List AR-14 lists Thunderbolt prices as....
1000AT Two Tone 240 volt 3 phase $6684.25
1000AT Two Tone 240 volt single phase $7514.25
1003A 3-signal 240 volt 3 phase $6907.00
1003B 3-signal 240 volt single phase $7716.75
RCM1A for 3 phase thunderbolts $837.00
RCM1B for single phase thunderbolts $837.00
RCM3 for 1003s $236.00
If you use the inflation calculator online the price for a thunderbolt isn't much more than a current model siren.
Proud owner of a garage full of junk.