an additional charge
I can say, without any data to back my opinon up, that I believe they are charging more than their current profit margin of 20.05%, on this product and feel that the odds of me being correct are high.
Apple has done this on several products in the past. Initial release is priced high, then later at some point, they drop the price and are still able to maintain a high margin. nothing wrong with this, just making a statement.
1) An up charge, in your context, is a very specific kind of increased charge, not any charge.
a charge or payment that is additional to the usual or basic price; a surcharge:
2) Companies typically have higher profit margins on BTO options for two reason: it lets them start their base price lower than otherwise would be possible to maintain a profit margin for a product and BTO options typically have much lower unit sales which can raise the cost per unit in sourcing with its lower the economics of scale.
3) People usually complain that Apple hasn't reduced their prices when Intel drops CPU prices or when a product is considered EOL but you're stating (and complaining) that Apple reduces prices later on. Give me an example.