LOOK NO FURTHER!
https://www.aliexpress.com/item/2255800164534876.html
Ran across this while looking for some good deals on 3.5 to 3.5mm cables. No, they're not in candy-colors and such, just black. But DAAAAAMN are they cheap! Around $65 got me a bundle of 50 cm and a bundle of 100 cm cables, shipping included.
And if your modular is big enough to serve as an efficiency apartment, they even sell 'em in lots of 1000!