Tempering nullifies the trade

Then don’t trade. Problem solved.

There is nothing intrinsically problematic about paying for a 1/3rd chance at an item you want than a 100% chance at the item you want; the price of the item the market defines adjusts as a result.

I will never trade in the game, because I don’t want to support RMT wallet warriors. I’ve still reached end game and killed the vast majority of the available content, and given more time will do the rest. Nothing compels you to take part in trading; it’s not needed.