My experience is that expensive speaker wire does make a difference if you have a system resolving enough to hear the subtle differences. And it's very system dependent at that level, as other choices of power treatment, room treatment, and other cabling create a need for a "synergy."
Cheap cable generally imparts a grainy signature that may or may not complement or impair the sound of a budget system. If you have a budget system, try a few cheap wires and see which is the best fit (i.e. dark or bright, etc.)
I long ago went on a search for great sound and I don't spend money on some things others do so I spend a lot of money on stereo equipment, it's fun for me. I've made some serious blunders along the way and I've learned a lot and the process was very enjoyable. I've enjoyed a spike or two in my bank account the last decade and I now have a system where I can fine tune with cabling etc. and really get great listening. And I'm happy. I wouldn't necessarily recommend this course for others, but I USE my system as much as I can, more than any other machines I have, and I have a huge collection of recordings and movies, tv shows etc. to utilize. And it's still primarily about those, getting the most out of them. My life has been greatly enhanced by this pursuit. Other things are very important as well, family, friends, romance, a place in the flow of the world etc. I think I keep most of it in balance.