Pogre,
Come on dude, you can own a classic analog SPL for $10 bucks. It doubles as a piece of audio history.
the Radio Shack analog version
the Radio Shack digital version
Granted, the digital version is no where near as cool as the analog version with the bouncing VU meter.
But the digital version is only $5 bucks. I have the analog meter from waaaaaay back in the day. Even as old as it is, it still works and looks like I know what I'm doing. I obviously have no idea what I'm doing half the time. If I could figure out which half of the time I do know, well, I'd have something.