It does not actually matter how many NFTs you have what matters is whether your NFTs are valuable or not, whether an NFT collecter sees your NFT collectible or not, whether your buyer sees commercial value or not. The value of NFT depends on the money a buyer, a collector, or an investor willing to pay for it. For instance, if you have an NFT and a buyer wants to pay 0.001 ETH, the price of your NFT is 0.001ETH, however, if you can find someone willing to spare 1 ETH, the true value of your NFT will be 1 ETH. Well, one of the major problems with selling NFTs is NFT collectors overprice their NFTs. If you have ever visited NFT marketplaces you will understand what I mean. NFT sales are also determined by the marketplace you are using. Opensea is the most popular and the biggest NFT marketplace, it not only has a huge number of sellers, but also a lot of buyers. However, it is also very competitive because due it is difficult to survive the competition. Rarible is also a good NFT marketplace, however, this is not as popular as Opensea, therefore, there is a dearth of buyers.