What's the most cost-efficient way to accept payments on my website? American Express will be the card of choice. Average sales order ~ $100-250. I am only in Alpha stage so I don't want to pay Braintree (or others) $80-100 / month, right off the bat (bootstrapping! )
Is PayPal my best bet?
Again, I will be receiving payments from corporate credit card holders via my website.
Does anyone know of any alternatives?
You should definitely at least look into amazon payments https://payments.amazon.com If you're just starting out i would definitely use something like paypal or amazon that have a very low initial cost, and upgrade to a different system if there's something left to be desired and you have enough volume to pay for it.
A site I help with (uk based) uses sagepay. Its a strong, reliable brand over here and they offer a range of integration methods.
Its also fairly easy to get to speak to a human being for help or to answer questions, I'm not sure how easy it is to speak to paypal directly.
