If you have to implement a payment gateway, how is it not a smart thing to carefully consider your vendor? That definitely seems like a priority to me.

I don't think there is any business decision involving costs that I want to make assumptions about or blindly select a "default option". Especially not one that represents a percentage of raw revenue.

The difference between a paypal implementation and stripe is not as significant as people make it out to be. I understand the intense paypal hate and it's well deserved, but from a pure cost perspective it often makes more sense than stripe.