I would take the thousand $1,000 coins every time. It is much easier to resell $1,000 coins than $1 million coins because you have far more potential buyers. Yet, 22 coins each sold for $1 million or more in 2021 alone. It must be great to be that wealthy.
Also, the true collector in everyone reading this (all three of you), even dealers, would love to experience the fun of handling and studying those thousand $1,000 coins.
And I can think of several coins, such as certain patterns, that you can buy for a mere few thousand dollars but should be worth $1 million yet never caught on due to the lack of marketing and publicity.