They’ll be fine as long as they aren’t damaged. I would say the biggest difference between cheap and expensive ones would be wire gauge and insulation thickness. Thicker wires with more insulation are going to last longer than cheap thin ones. Think of stuff in your trunk smacking the wires or the wires being bent or getting slammed in your hood or any number of things that could potentially damage them.
Cheaper ones won’t be inherently unsafe out of the box but over time are going to be more prone to damage, which can either just make them not work or make them arc somewhere you wouldn’t want them to arc potentially causing damage or injury.
So basically just check them before you use them. Which you should do with any wires in any application honestly. Make sure they’re not nicked or have exposed wires somewhere along the line