I know you’re trying to drive home a point and i agree, but is this really feasible for under $1,000? I’d estimate something with these capabilities would be in the $20,000 range at a minimum.
The problem is the bar of effort. Bombs are even easier to build, yet few with the will to build one for nefarious purposes seems to be effective in doing so, even with provided materials (without training, see IEDs). Same with guns, tanks and other complex items. Anyone can make a gun from hardware store items, but most criminals will steal one instead. The impulsive instinct that drives most crime seems a burden on complex tasks.
I had a friend who was making black powder as a schoolkid, and he actually had the police turning up at his house to ask questions about his purchasing history - which is a small sample, but it fits with the basic intuition about how you'd stop people from building bombs: make non-household bomb-making stuff impossible to get hold as a private individual, then just monitor people that make weird purchases of the chemicals that remain.