setCost() vs listing on Opensea

[ElDla]

I am just a bit confused about these two and want to be sure that I understand it right.

When I set the cost inside the contract or change it later with setCost method on remix, this is the cost for minting (for example the cost to mint nft on the Dapp during pre-sale).

Meanwhile, I can only manually list for sale and set the cost on Opensea for those that are pre-minted (for example the rest of the nfts inside the same collection that weren't sold during pre-sale and that I have to pre-mint so they show up on Opensea).

The cost in the contract does not affect the cost I set on Opensea in any way (?)

Is my understanding correct?