I recommend reading up on the Audioquest line of connecting cables. They do a lot of R&D on the type of materials for the underlying metal and in the platting process. They also do a lot of R&D on insulation type, grounding materials, and noise dissipation. It's the noise dissipation that will provide the most sonic improvement for your system. Audioquest makes a number of models that are not terribly expensive. Of course, they offer a number of models that also approach stratosphere price points. I have been using their line of products for more than 30 years, since the company was very young, and have always found them to be superior in so many ways, especially sonically. I have always bought new product but you can easily find them used, on eBay, for about 50% (plus or minus, depending on age or demand) less than the price of new.
Good luck. No matter which you settle on, do enjoy the music.
Good luck. No matter which you settle on, do enjoy the music.