Kogan is currently selling 1m USB to micro USB charging cables for $1 each, down from $9. Shipping is free, depending on where you are.
Stock is limited, so you’ll need to get in quick.
Just keep in mind that your new cable/s won’t even leave the warehouse for 3-4 weeks, so if you need a new cable right now you’ll need a more timely solution. On the other hand, making sure you have a spare is always a good idea, especially for $1.