Hashlips NFT Contract

[0x0fly]

Good morning everyone. Unfortunately despite the video tutorials, I still have some doubts.
What is the difference between the 2 variables highlighted in bold?

To make you understand.
I would just like to publish 11111 nft, available immediately, at the price of 0.02 Weth, only 1 existing NFT for each object.

After posting, for trying the contract on the Mumbai testnet, I logged in with another profile to view the collection and I only see the MAKE OFFER button, instead I would like to see the price of 0.02 weth which instead I do not see present.

Thanks in advance for the support.
Greetings

string public baseURI;
string public baseExtension = ".json";
uint256 public cost = 0.02 ether;
uint256 public maxSupply = 11111;
uint256 public maxMintAmount = 20;
bool public paused = false;
mapping(address => bool) public whitelisted;

constructor(
string memory _name,
string memory _symbol,
string memory _initBaseURI
) ERC721(_name, _symbol) {
setBaseURI(_initBaseURI);
mint(msg.sender, 20);