Is a high priced Line Conditioner needed

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-

I, also, have two dedicated lines for my analog/tube system. Everything plugs into the Furutech outlets directly. If a Midwest thunderstorm shows up, I turn stuff off. The closest I could get to no sonic impact was a Brickwall. But, it sounds better without.

The bottom line is that your dedicated lines do NOTHING to remove or address spikes, surges, power sags, EFI and RMI riding in from outside your home (although they do reduce interhome interference). In other words, yes, you do NEED additional filtering and protection. I have two power regenerators in my systems and they work quite well to protect the systems and let them sound their best.