Depending on the level and type of sneaker, the cost to pay is calculated per unit of $RUNGEM (or $RUNNOW), or possibly both.
Upgrading NFT Cost
Minting NFT Cost
The cost will go up as the level and rarity of the sneaker increases, and so will the reward.
BUY NFT Sneakers NOW to earn great benefits: https://marketplace.runnow.io/boxes-by-team
ROI Calculator: https://mediahub.runnow.io/earn