Can I resell FiveM scripts?

The confusion comes from treating a script like a game copy. A FiveM script is licensed, not sold: the seller keeps the copyright and grants you the right to run it under stated conditions. Reselling, sublicensing, renting, or posting it — modified or not — is outside that grant with nearly every seller, and doing so is what the market calls leaking. Most licences terminate immediately on a leak, and a seller with an order system can revoke the grant and record the action.

Escrow makes the question moot for locked resources. The encrypted files are bound to the purchasing account through keymaster, so a copied folder simply will not start on another server. What people sometimes resell are the open files, or a de-escrowed dump, and both are redistribution of someone else's code regardless of what the buyer paid for them.

What is sometimes possible is a licence transfer: when a community changes hands, some sellers will move the grant to the new owner's Cfx account on request, and the official marketplace and keymaster may support this for particular assets. That is a seller decision, not a right, so ask before assuming — and if you are the buyer of a second-hand server, confirm with each seller that the licences came with it. A server sale that includes "all the scripts" without those confirmations includes nothing you can legally run.