Member story
When you can convince the seller or buyer that it is beneficial for them to work with you, then you will already be in control of the situation and set your own rules.
If you are selling, then let them know that you have a lot of buyers, and they should hurry with payment. And if you buy, let them know: you can afford to choose as much as you like, because there are plenty of options, and let them themselves show that their product is better. And you need to do this, even if you have no choice. Especially if there is no choice.