Almost no e-commerce websites force you to buy and ship every item individually. Instead, when you’re shopping you add each item to your virtual shopping cart. When you check out, you purchase them all at once and they’re shipped together. This makes the process simpler and saves on shipping.
OpenSea should add a similar feature to its website for NFTs. When the gas cost for purchasing an NFT is some high amount like $80, that strongly discourages me from purchasing multiple NFTs, even though I want to. Why not let me buy what I want all at once, bundled together, so I only need to pay one gas fee for the whole set?