how much should you spend on cable?

Here for some cable science: http://www.roger-russell.com/wire/wire.htm#introduction

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...