This replica of the Star Trek "Medical Tricorder" makes it clear why they rarely showed a close-up of Bones' device on the original series: It looks like something cobbled together in the garage of that neighbor who's still trying to get his old CB radio to work.
It's interesting to note how a supposed 23rd century device created in 1966 could look like something made in 1967. (Is that foresight-hindsight?) Anyway, if you want one of these collectable novelties, GeekAlerts says it can be had for just $40 in October, complete with removable scanner. That's a bargain because, with inflation, it'll probably cost over $1 million in 200 years.