With trading. Market price is not only price. With skins there are lot of preferences. Starting for weapons they apply, not all people use same guns as much. And they might prefer one style of skin over an other skin.
If you are not in to extract most possible value, you might trade a more expensive skin for weapon you do not use in style you do not use for less expensive one for weapon you use more in style you really like.
If you are not in to extract most possible value, you might trade a more expensive skin for weapon you do not use in style you do not use for less expensive one for weapon you use more in style you really like.