Selling Necrosis

I am a new beginner, and was in Detlas when I picked up this unidentified legendary. I didn't think too much of it until I went to unidentify it, and got Necrosis. Mind you, I don't know a lot about this game, and I only just got gold armor, and decided to sell it on the market instead of the blacksmith. When it said it went for $4710 in the market, I was so surprised. I am instead selling it below, at $4000. I don't know if that's too little or too much, but yeah. Its in the market for $4000.
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Turns out, market tax means it's now $4200.

 

Could you show it please?

 

only good necrosis sell for that amount, bad necrosis or even meh ones are blacksmith