No its not.It would be business killer for Warmane exactly for that reason.
To buy full t5 set it cost 130 coins,if you buy items from the store.
Imagine now someone selling t5 char for 50 coins,and that would happen rest assured.
People don't respect themselves,their time invested and put into gearing character.Once they get bored,or need coins to gear alt/main,they would sell full t6 char even for 50 coins,in order to sell it asap.
Minimum prices are set by Warmane based on the gear that your character has. If you have more gear in bags, selling it without inventory will have lower minimum price. If you want to sell it for even lower price, you can unequip some items and sell it without inventory.