Is a high priced Line Conditioner needed

Personally I wouldn't put anything in front of my amp. I use a power conditioner for the preamp and all other components. I also keep my video(tv & cable box) circuit separate from my audio. Video's audio I prefer to use toslink into the DAC rather than digital coax, from the DAC I prefer balanced or RCA interconnects to the preamp. I'm a 2 channel person for what it's worth.
On a budget I would look at the Furman Elite 'i' series over the monster, I believe price would be similar. Downside either way is they're both made in the orient? > laffs

Precisely Minor1.

those Monster conditioner products steal the current from your system, more to the point, power amps.

There is only one power conditioner that can really deliver, that won't limit a large power amplifier. It was made by Elgar and was for industrial/commercial purposes, so you have to find one used on ebay, and may have to get it refurbished.

It is mechanically noisy, so you have to place it near the breaker box in your house, and run the wiring from it to your audio room. You might have to have an electrician do the work.

However. It is easily the best made, and the 3006 can deliver a perfect sine wave at full load of 28Amps at 117Volts. Seems to me there is a 1KVa version as well. No noise, no distortion, no spikes. The principle of operation is sophisticated- well beyond what typically passes for 'high end'. It uses an isolation transformer, a precision 60Hz oscillator that is synchronous with the AC line, a power amplifier and a comparator circuit. If the output deviates from the reference oscillator, a feedback signal is created and applied to the feedback winding on the transformer- the result: a low distortion sine wave free of noise.

This is the only conditioner I know of that can handle a set of our MA-2s or MA-3s. Most conditioners I have heard mess things up even when presented with our M-60s as a load, so usually I recommend plugging straight into the wall unless you have an Elgar.

Jafant, the 'middle of grid' is absolutely irrelevant to the quality of power. The quality of delivered power depends on power lines only. The age of power lines, connectors, isolation, type having the most of impact. Some of the powerlines, depending on 'who's the boss', don't get maintained on time and properly to preserve better profits. They're highly affected by wind and other weather conditions so they could 'kiss' each other and create a surge in nearby dwellings or kill transformer and create outage.

Moved to a new home 3 weeks ago and have just installed an upgraded dedicated circuit. Main panel is Cutler-Hammer CH series with copper bus bar, subpanel is GE Master Load Center with copper bus-bar. The subpanel is tied to the main with massive 6/4 conduit and I'm using 10/2 Romex (for now,...other options too pricey at 16-25 dollars per foot, with 5 outlets I needed about 150 feet of cable) BUT I have installed an Environmental Potentials EP-2050 on the main house panel to protect everything and an EP-2750 Ground Filter on the dedicated circuit. I have heard nothing but good things about the EP units and that combined with the copper busbar panels should be a nice upgrade in the entire system's sound....very excited to hear the result once i finish unpacking! I'll still be using my Purepower 2000 on the system as a whole but may go straight into the wall for my Edge amp and amps in the Legacy Aeris towers. Ultimately I think I'll move to a Running Springs Audio Dmitri but time will tell if this move can happen....