Do speaker cables really make a difference ?

I was using 10ga speaker wire from the hardware store. I thought it sounded good until I bought more expensive oxygen free copper 10ga Speaker cable. The highs were much more defined. More clarity and detail in the midrange. The bass was about the same, but it seemed as if the amp has better decay and recovery of deep notes changing pitch. It seemed faster responding if that makes sense. My budget is tight so I get what I can afford. I have no idea how much $$ =how much better sound or the cut off $$ before you split hairs? I spent about 2X for the new speaker cable.  All I know in my case the the of speaker  cable did make a difference.