Since the BTC transaction fee is 0.0001 BTC, here are what transfers will cost in the future:
$1,000 per coin = $0.10 transaction fee
$10,000 per coin = $1.00 transaction fee
$100,000 per coin = $10.00 transaction fee
$1,000,000 per coin = $100 transaction fee
Honestly, if Bitcoin goes to the 6-7 figure mark, I don't see how people would be willing to pay these fees. Especially for everyday transactions. And considering there aren't enough Bitcoins for everyone in the world to own even a tenth of a coin. Comments?
When Bitcoin's value has reached that stage we will have several sidechains and lightning network, payment channels being implemented. And there you will do your micropayments and more smaller transactions.
At least this is my actual view how things could evolve.