Yes, you need a premium membership to trade on Roblox. The Trading System is exclusive to users with a membership. This allows you to exchange Limited or Limited U items with other members.
Premium membership also lets you trade Robux with other users. This can help you get the items you want more easily. The trading feature is quite popular among players who collect rare items.
With a premium account, you can send trade requests to other users. You can also counter offers if you think the trade is not fair. This gives you more control over your trades.
Moreover, Premium members receive a monthly Robux stipend. This can be used to buy more items or trade for better ones. Having a premium membership truly enhances the trading experience on Roblox.