I've heard people talk about trading sprees and something about selling things for credits. Now I didn't think that was possible..
So, what exactly are trading sprees?

Two ways

Trading credits via Quest Machine.

Buying buyables equal to the amount of credits the spree is.

Say somebody offers 4K (4,000) shopping spree for your item and you accept. You then pm them a list of things from the shops that add up to the 4K. You then trade them your item for the buyables you requested. This is the only way you can trade on these boards.. Kiosk trading is not allowed here and VMK do not like it either, you can get scammed too easily that way.

The selling things for credits is different. Click on an item in your inventory and it comes up with "place" or "sell". If you sell it then VMK gives you credits for it, but be careful, they never give back what you paid for it.

Two ways

Trading credits via Quest Machine.

Buying buyables equal to the amount of credits the spree is.

About the buying buyables, if you sell that buyable, you get 1/5 of that amount. So say you bought an item for 5,000 credits, you sell it and get 1,000. So about the buying buyable is not true, I think.

Oh, okay that makes more sense then what I came up with in my head.