Best Speaker cable in the $400.00-$500.00 range for 2 meters

12 gauge Duelund Tinned - copper in cotton, or Goertz, both were designed for audio by real engineers. You can use Western Electric, the original, it's what I am listening to now, but I am told Duelund is better, all my ICs are Duelund. There are now Western Electric fakes, so if you buy W.E. I recommend buying from;


https://www.ebay.com/sch/tajacobs/m.html?_nkw=&_armrs=1&_ipg=&_from=

If using Goertz USE THE ZOBELS! Goertz like the old and much vaunted Polk cable, is almost purely capacitive and can send amplifiers into oscillation in inaudible frequencies, which can destroy you amp. I have used Goertz for years, WITH ZOBELS! I haven't yet done an A/B, but both sound like they don't exist IME. Other cables do seem to impact the sound, so if you are trying to cover for other issues, keep looking.

I have a Rogue Stereo 90 (modified slightly) driving the electrostatic panels of Martin Logan Vantage speakers. I recently bought Morrow SP4 cables which are currently still on special and am totally knocked out by the improvement to my sound even though they are not fully burned in yet. And best of all you get 60 days to try them out and if you don't like them you can get your money back. The SP4 cables are well  under your price level and sit around the middle of the Morrow range.

Check out Blue Jeans Cable for their offerings

I drove my Avalon Eidolen speakers with a Rogue amp connected via several cables until I settled on AntiCables. Serious bang for the buck.

(I subsequently replaced the Rogue with an Ayon Triton amp, but kept the cables.)

Look at SignalCable.  I have a set of Silver Resolution.  Very impressive, very affordable.http://www.signalcable.com/