Trader Goh's Pawn Shop 411 and FAQ

Zynga makes an article about this on Support Page..
Trader Goh's Pawn Shop 411 and FAQ 

A new way to trade and earn items has finally arrived! Trader Goh's Pawn Shop is the latest addition to the marketplace and allows users to trade in unwanted inventory for more useful items. The time is now to review your inventory and visit Trader Goh and see what his Pawn Shop has to offer!

The Trader Goh Pawn Shop can be located in the Marketplace. Upon first entry be sure to allow Trader Goh to walk you through at least one trade to gain an understanding of how this feature works. The '?' icon in the upper right hand corner can always be selected for additional instructions on how the pawnshop functions.

Pawnshop Items can be purchased from Trader Goh with a combination of reward points and different amounts of items (common, uncommon, rare, and superior) or directly with reward points. Trader Goh has a strict policy so be sure to review the items being traded away before selecting 'Make the Trade.' A trade transaction can always be canceled by selecting 'X' in the upper right hand of the trade window.

Here is an outline of the requirements for an example trade:

Name of Item with Stats: Example Item (Superior) 72 Attack, 49 Defense
Required Items to trade to Trader Goh:
- 1 Common Items
-3 Uncommon Items
-2 Rare Items
-3 Reward Points

Once the appropriate items have been selected from a player's inventory, initiate the trade with Trader Goh by selecting 'Make the Trade.' When this has been completed a second confirmation will be prompted. Confirming the trade will permanently remove your selected from your inventory and add the new item.

FAQ

Where is Trader Goh's Pawnshop?
The Trader Goh Pawnshop can be located under the marketplace tab

Why do I not have access to Trader Goh's Pawnshop?
The Pawnshop becomes accessible when a player reaches level 20. In addition to the level 20 requirement, the Pawnshop will be gradually released to all players. For a short period of time a small group of randomly selected users may not have access to this feature.

Are trades reversible?
Trader Goh offers two levels of confirmation before completing a trade thus all trades with Trader Goh are final.

Can traded items be gifted?
Items earned through trading cannot be gifted

Is there a trade limit?
There is no trade limit. An unlimited amount of trades can be completed with Trader Goh