Poll: What impact do payment fees have on your margin?

I've sold things on the internet for a long time, and I know the impact fees have had on my businesses - but I'm trying to get an idea on how much it's affecting other people's businesses. I've seen 20% (cart size around $20, margin around $5) to as much as 300% (charging on top of existing Credit Card fees, like Stripe does).<p>Pretend you charged the same price but had no fees - what would the impact be on your margin?