Minus, the A-bomb is not as simple as it is pictured in school Physics text books.
Even now, with all he modern microelecronics that is cheap and efficient, it is impossible to make a Bomb without special devices, like "cryotrones" etc. Weapon Plutonium is a very rare and expencive substance, and I doubt anyone can buy it, maybe in Hollywood movies only. And you have to design an extremely precise and reliable detonating system, that includes many stages from shaping a plutonium "charge" (an impossible thing even in a lab with modern chemical and physical equipment) to making conventional-explosive "ignition" charges without any mechanical defects and testing the detonation system. First A-bombs costed many times the cost of the TNT that had the same effect (20,000 metric tons). It took USSR four years to make a Bomb, and it took the effort comparable to the Great Patriotic War.
Even a mass-production of "conventional" explosives is impossible without equipment and technology that costs millions dollars, requires highest-grade engineering personnel, and is extremely specialised. It is impossible to produce, say, 100 tons of ballistite gunpowder or even such a primitive substance as trinitrotoluene in Afghanistan now.
