Yeah, depends on where you shop but right around $5 is what I paid.
This thread outlines the process and items you need.
I got the USBASP off ebay for $2.xx, the soic8 clip for another 2.xx off ebay. Then the ribbon cable I won for like $.50 cents at auction on ebay.
Then all you need in a computer with a USB port (heck might even be able to do it on an andorid phone now days, although I have no idea if that is actually possible).
To flash a pre-built hex file such as the bistro files for the Texas Avengers drivers or TK’s biscoti hex you simply run AVRdude and don’t even have to install anything.
Now if you want to edit the firmware that gets a bit more complex but still not super hard. Although it will take more then novice level computer skills.