If you're worried about the cost of CC charges, then you're probably not charging enough for your product in the first place.
Its one way to look at it.. but suppose you have $10,000 a month in sales and you're losing 3% on each transaction.. that amounts to $300 every month. I don't know about you.. but I would hate to be throwing out $300 every month. You can call it the cost of doing business, but if there is a better way... I say go for it! I mean does it matter if you order your ink from Adorama, B&H or Atlex? Its the same ink from the same manufacturer. Likewise, a transaction run through Paypal, or Visa, or MC or some other form is all the same, unless of course the customer doesn't like your options for forms of payment. I would rather take cash and save the 3% any day!
I guess my point is, the more sales you have, the more each 1% matters.