Without making any quality comparisons, I would just point out that the tasting menu at the Waterside Inn, Bray in the UK (three Michelin rosettes/Roux) is over £200 and Alain Ducasse at the Dorchester will set you back £450 plus. Arnaud Lallement's restaurant in France will charge you Euro 235 for a set menu very similar to that in Enchante (for example,tomato dish and squab pigeon) plus euro 135 for the wine pairing. All of these are three star Michelin establishments and that is what it costs! I also think the level of upcharge reflects how small the allowance is for each meal in the MDRs?
As for the charge for soda, it is common for soda fountain drinks to be free but in many bars/restaurants on cruise ships they use canned sodas and once they open one of those, they charge!
Finally, I note that I see many Americans very often drink cocktails with their meal or will drink soda, refusing wine. Without any judgment, I will only state that such an approach in a French restaurant (of pretty much any standard) would be regarded with horror however well the staff concealed it. That is just a cultural thing, sorry.
Now Arnaud Lallement is a three star Michelin chef so presumably that is what Disney is aiming at? The proposed price is not unreasonable, IF that standard is sustained. DIsney's success (or not) is for others to judge as I will not be travelling on the Wish any time soon: three and four night cruises are not for me.