Arduino or Raspberry Pi are kind of overkill for this ...
USB breakout board -> MSP430 -> LEDs/Buzzers/Whatever
You're talking somewhere around $14.
Yes, you'll need to know C or assembly for the MSP430 and likely a scripting language for the PC, but it makes a lot more sense than bringing in all of that horsepower to essentially get an I/O and light an LED.
Your solution works totally fine, but it also involves using an entire computer to run the thing, which may or may not be overkill depending on whether or not you already have a computer that can be dedicated to it. Personally, I prefer these kinds of projects to be self-contained.
USB breakout board -> MSP430 -> LEDs/Buzzers/Whatever
You're talking somewhere around $14.
Yes, you'll need to know C or assembly for the MSP430 and likely a scripting language for the PC, but it makes a lot more sense than bringing in all of that horsepower to essentially get an I/O and light an LED.