Best Power cable around/prefer under $300....

If you like DIY and can stretch a little, you could check also a Furutech FP-3TS762, a 10AWG screened cable and copper FI-11/FI-11M connectors. 1,8-2m works perfectly fine.
G

BLE Design on Ebay. OFC 10 gauge. Rhodium or gold connectors. $39. Looks great. Sounds great. You can tell your friends it was $300 and spend the rest on music.

Definitely Shunyata. But I will suggest stretch the budget a bit, and get the Venom NR v10. 

This makes it probably the only one mentioned you could buy and use several years then sell and not lose money.

In my experience every cable I’ve ever bought used I’ve been able to sell years later and not lose money. Most used cables can be had for 50% or better off new. I’m sure the Master Coupler is ok but there’s nothing special about a SR Master Coupler in regards to resale against other cables.

What is peculiar though is if you look at usedcable.com right now you will see there are 11 Synergistic Research power cables listed for sale....more than double that of any of the 18 other brands listed in their inventory. Makes you wonder why people are unloading them in such volume or why they can’t get rid of the inventory easily either. No opinion here...just stating a fact.

https://www.usedcable.com/power-cables.html

I can easily explain this for you, based on some insider talk I know for sure: Peter, the guy at The Cable Co., which is the owner of Used Cable website, used to work for many years for Synergistic Research. Which means that’s where all SR surplus go first.

Also, typically, high volume manufacturers, not just cable manufacturers, tend to have much more listings on used market than low volume manufacturers. Similarly, low volume manufacturers, not much available in used market. This is just a fact, reality.