Re: Chargeback fees - Visa acquired a company called Verifi a few years back. Their new products are Rapid Dispute Resolution (RDR) and Order Insight. RDR effectively lets you automatically refund a transaction before it gets turned into a chargeback and Visa charges a $4 fee (Assuming your MCC code is not high risk). Order insight lets you provide certain data about a questioned charge immediately and if the customer has had 3 previous charges with you, a chargeback CANNOT be issued.
It was a really easy decision for our business based on win rate, avg order size and chargeback fees. Plus now we don't have to constantly worry about Visa's or the merchant bank's 1% chargeback rule. This only applies to Visa charges but it represented about 50% of our total volume.
One last note - Visa is basically taking away a massive revenue source for the processors. If your processor is TSYS, they are trying to charge a RDR fee of $10.