Here's an interesting trade-in offer from the Microsoft Store -- for a limited time, you can get $200 (or more) in gift cards for your old iPad.
To redeem, bring your gently used iPad 2, 3, or 4 in to a Microsoft Store and they'll give you a minimum of $200 in gift cards in exchange.
This offer is valid through October 27. To be eligible, you will need to trade in your power cord as well and your iPad cannot be password protected. Trade-in value is subject to Microsoft's discretion and store-manager approval. Limit of one trade-in per customer, in-store only. For more information, visit MicrosoftStore.com or one of the BC, Alberta, or Ontario Microsoft Store locations.