best exchange to purchase 900k in BTC?

possibility 1:

Robinhood with "free commissions" and instantly switch to a pockets

possibility 2:

Kraken or Coinbase and pay, by my estimates, 13,000 USD in charges (I’ve a screenshot of Coinbase charging $500 per 35k buy so 13k in price's for 900k buy) and instantly switch to a pockets.

it appears possibility 1 is finest… however can anybody inform me if there's something flawed with that? and sure it assumes Robinhood lifts the switch restriction (which is already achieved)

thanks

https://preview.redd.it/v3jtfsjmoxdd1.jpg?width=1179&format=pjpg&auto=webp&s=1906b2551713eeaf6927dae8855242f0929862d8