The magic of pushing for more competition only works if consumers do their part. Our greatest power in any buy:sell transaction is the ability to say "NO" which is a few notches superior to the great power to "shop around."
If "punishment" through higher pricing conspiracy actually plays out, consumers can easily choose NOT to overpay the added costs that would be asked. "NO" is at least as easy to say as "YES." And if enough exercise that power, sellers always fold. Why? Because at the climax of the transaction, sellers want the revenue MORE than any consumer should want the "stuff."
Even the fan-iest Apple fan will have some price limit that is their straw. Else, bring on $2K iPhones and $3K iPhones and $10K iPhones if people will pay any price, whether to cover added costs or just because Apple wants to fatten the margin even more.