how much should you spend on cable?

There's that science claim again. 😩

A person with limited funds should buy the most expensive cable they can afford. 

There's more truth than humor in that statement. Think about it. 🤔

All the best,
Nonoise

From the Roger Russell screed on everything you never wanted to know about audio cables:

KIND OF WIRE MADE NO DIFFERENCE

It can be solid, stranded, copper, oxygen free copper, silver, etc.--or even "magic" wire--as long as the resistance is kept to be less than 5% of the speaker impedance. There is no listening difference as long as the wire is of adequate size. Bear in mind, as previously mentioned, a well-designed amplifier will not have a problem with any of these wires.

That's terrific. Now I can stop worrying so much about the coat hangers I'm using for cables.

You should spend between $10 and $20. If you spend more, then you are wasting money.

If you will read post here on cables, many true audiophiles do invest on good cables, my main system is about 30k. I spend $700 on speaker cables Cerious speaker cable, ic teo game changer used $445, HF Reveal ic $699, Pc cables dcca ref $400, mit pc zcord x2 $200 . On my second systems 10 k system I spend $60 anticable sp cable, $30 diy single, $150 single clear day speaker cable, pc Vd nite pc used $300, mit $250 ic, silver star dig cable, siltech ic $139.on my second system I got lucky this system has weird cabling but it's so dynamic...

It's worth to experiment cabling to your system, true ,expensive cables don't give you guarantee they will match your system. My friend told me to loan different cables,so you learn what cables match your system or your taste.This the only way ,  you will find out what price you are willing to pay, for the performance on each cables...