5 billion
That depends mostly on the instrumentation you want to collect data on the test blast. The bomb itself is cheap.
For America 5 billion dollars For Russia 1 favor
The first atomic bombs cost billions because they had to learn how to gather uranium and plutonium into a form that was good enough for a bomb and they had to design the bomb. Now a nuclear missile cost would be probably about a million or more. The cost of the newer missile is in the housing and maintenance of the missile.
Yes, the radiation was much more abundant after the atomic bomb.
Read Richard Rhode's book: The Making of the Atomic Bomb, it will explain it in much greater detail than anyone here could.
Alot
An atomic weapon unleashes the power of the sun.
60,000-80,000
It depends on the size of the bomb
100,000,000 kilojoules
alot alot alot