Nftby.me Would it be better to sale it to someone who sales Nft's? Or would it be better to develop it? I'm kinda new at this so any suggestions would be greatly appreciated.
.me is not a good tld. It would be much much better for you to get a .com domain. There are still a lot of them for sale or even to be created. Think about it. Every big site in the world. Every big and successful site is a .com site.
I don't have a problem with the .me extension - it's how it fits with the business it represents that is more important. We know nothing about you, your experience with NFTs, nor your credibility in the industry. You might be new to creating websites but an influencer in that field, in which case exploit your good name and create a site. or you might be new to NFTs in which case you'll need a solid business plan to identify how you can serve that niche. Once you have that you'll know if .me is right or not.
Despite of domain name extension web site itself makes it popular or not. So if you have current offers for that domain name - consider them and decide if that worth to sell. Development requires such very demanding resource as time. Domain name is registered for 1 year. You may spend much more for learning the stuff and developing your domain name. So decision is always yours.