Summary

Vulnerability Details

The documented price for buying an NFT is 2e18, while the actual function code burns only 1e18 and The documented token reward for "extra nice" users who collect NFTs is 2e18, while the actual function code mints only 1e18 tokens. the purchased cost that was declared was not used.

Impact

This discrepancy is a critical issue, as it could lead to user dissatisfaction and a lack of trust in the platform.

Tools Used

manual review

Recommendations

Update the buyNFT function to burn 2e18 instead of 1e18. This will ensure that the price of an NFT matches the documented price.
Update the collectNFT function to mint 2e18 tokens for "extra nice" users. This will ensure that users are rewarded with the correct amount of tokens, as stated in the documentation.