Got a hunch this will turn into a "taboo-topic", but this is something of interest to me as well. Mostly, I want a cheap and easy, reusiable means to ignite firecrackers remotely. For the remote, I was thinking about modifying a cheap Big Lots R/C car, and using a 4017 to index through 10 shots. Basically the neighbor's cats (17 or so) like to use my yard and garden for a toilet. Some are sensitive to ultrasonic, some bright flashing light (xenon flash), all hate the firecrackers, which I have a huge quantity. Basically, it would be more effective and convient to push a button when I see them on the security monitor.
Anyway, how much range are you looking at? How big an explosion? Not sure $10 will buy you much range or safety. Personally, if its a big boom project, I'd seriously consider a two channel system, one to arm, the other to fire.
Since, I don't know the details, can only guess this is for some kind of hobby interest, not just a couple of tree stumps in the east pasture... Might consider timers, cheap enough to destroy...