Nope you don't need to pay on ROBLOX certainly its a free game.And also to upgrade your ROBLOX account you can buy builders club. Hope that helps
Bloxland but you have to pay after the free trial.
No i dont think so
There is currently no way to "Trade" items in Roblox. If you mean do you have to pay money to sell items: no you do not. The only money you have to pay to sell items would be the builders club subscription that you must pay to unlock the feature.
You can't.