Often the really good power cable,mains is fairly thick
nordost standard is 2x16 awg or 3x14 awg, odin and odin 2 7x14 awg an 7x15 awg i guess it's not always because they are used with big power hungry amps but because it also makes a differnce in sound quality.
A cable like Merlin Tarantula MK6 is 3x2.5mm, thats alot compared to 3x1.0mm or even 3x0.75mm (£50 for 1 meter £110 for 3 meter) so i guess it does matter somehow if a power cable,mains is thick or not and who would have a big power hungry amp and use only a £50 power cable even rated high enough in wattage ?
http://merlincables.co.uk/tarantula-fe/
I thought the plugs where the most expensive on a power cable,mains but going from 1 meter to 3 increases price by more than 100% (Merlin Tarantula MK6)
What are power mains rated for? (The once i have looked at doesn't have any specs on max wattage only amp, which often is 10 or 16amp and that is more about 2500watt for the 10 amp cable? So even the cheapest nordost, merlin could handle a 2x500 watt or even 2x1000watt form a "big amp" ? So 7x14awg is more for sound quality than how much power,amp,wattage it can handle? )