We made these stinky CDs / 'portable heraldic banners' using banana-sceneted oil and releaed them in September 2020. We then charged exactly how much it cost to make:

Flag - £2
Pin - £0.04
Paper - £0.03
Ink - £0.06
Cd - £0.65
Stickers - £0.07

Therefor, “ultamately” each disc cost exactly £2.85.