>>: The reason given for the increase over the agreed original price
>> was that Visa charges six percent for each transaction.
> 
> Most credit card companies discourage their vendors from doing this,
> for fear of exactly the reaction you are having. You might try
> calling up VISA and reporting it.
> 
> Dworkin

Indeed, you should report it. Being able to accept credit
cards is very important to mail order type merchants, as you can
imagine.  As I understand it, to get approved for  VISA, merchants must
agree not to raise prices for VISA customers.

(Note however, they can offer a discount for cash, as many miniscule 
profit margin computer sales places do here in the DC area. Splitting
a hair, I suppose: you can't bump up the price for VISA, but you can
offer a cash discount. Still, I'd report them, because the
bottom line is  they upped you for using VISA.)

Tom F.