Or do as Tinder, and charge 30% more in the app compared to their prices on tinder.com
Apple saying "it's giving the users more options" is total BS.. it's all about getting their 30%, because if you play by their rules, and give the customer more knowledge that you're being forced to charge extra because of this payment option.. then Oh noes.
A great example outside the app store is some credit cards charge much more than the others, so some stores charge you that on top. "You want to use X card, sorry but there's a surcharge for that card.. you could use something else.