Is a high priced Line Conditioner needed

I'm not sure what you mean by high priced, but:

I currently use a PS Power Plant Premier which can be had for about $800. I have been in this townhome 3+ years and have dedicated lines. Until I installed the PPP, there were easily heard changes in the sound of the system at various times. Most notably, there was a hardness in the upper mids that would come and go along with quick listening fatigue. The hardness was there more often than not. The PPP has removed the hardness and solved the listening fatigue issue for me.

In my previous two houses, I had dedicated lines fed from a Topaz isolation transformer (fed from the electrical panel) and that was all I needed for stable consistent good sound.

You won't know if your system will be improved or by how much it will be improved unless and until you experiment.

I have an audio store in my house, literally, and I went through the same thing.

I ran dedicated lines not because I wanted to I had to old house. I then tried different brands of power conditioners till I found one that I really liked, long story short I won't listen to a system plugged into a wall the sound just sucks.

A good power conditioner is mandatory for good sound.

A Monster is crap and will muck up the sound.

Stay away from power regenerators. It wll defiinitely be a waste of funds.

Several factors will enter in to it. Where you live and how dependable is the power. What equipment is hooked up to it. I had a Monster surge protector several years ago and it really made the music sound bad. I have no experience with their newer products. I would check out PSaudio stuff, They have a 30 day full refund if not happy. With a wide price range and friendly staff to work with and very helpful.
Good luck Pete

It seems you are ok with your sound. Why not just enjoy? Of course there will always be improvements; like a 2014 Ferrari should be better than a 2013. This music hobby could get to be like owning a high maintenance yacht-simply a place to spend money-