Best way to buy speaker cables and to evaluate them

I've been researching this for some time now. Some people recommend using the lending library at The Cable Company (5% charge will add up fast) to evaluate cables and others just buy used cables and resale them if they don't work out at a small loss or break even. Others recommend establishing a relationship with a local vendor and borrowing from them. Unfortunately I cant do this last one since I have no large dealers in my immediate area. 

Being a lifetime audiophile I know cables are a very controversial subject so please if you are in the camp of not believing they make a difference please don't respond. I have no real direct experience in comparing cables so I want an avenue to evaluate cables without the risk of being stuck with something that makes zero difference. I also understand some companies offer a money back guarantee on their cables and this is certainly an option. I was curious what most people do?

I'm just using a simple Belden 10 AWG blue jeans cable right now but am curious what people think of upgrading this cable to something better. The other cables in my system are of higher quality, Triode wire labs power cables, Zavfino Fusion Balanced interconnects, and DH Labs Silver Sonic USB cable. Cables I'm considering (New or used) are Zavfino OCC Silver Dart, Zenwave SCR-11, Acoustic Zen Absolute, Audience Front Row, and Cardas Clear.

What kind of improvements could I expect by going with one of these cables? I would love to get some better air and transparency or soundstage if possible. I'm pretty happy with the bass. Any recommendations on what route to take or with anything on my system is appreciated. My system is in my profile.