Need suggestion about Ipad 3- A1430

Sorry as I know I'm too much relying on this site for this kind of stuff. We were searching for an Ipad, (actually for me so I can use that for down loading so many rebate apps). So dh has an offer for a new Ipad 3rd generation modal 1430 , 32 GB for about $325. dh brought that home for showing me and its in brand new condition and is working fast.
Now I need experts reviews as never try Ipad before.
1- Is that a fair price. I checked on ebay, kijiji etc and it looks fair.
2- More important thing I really want to know, can I download and use rebate apps like save.ca ,zweet etc. As this is the main reason for buying that.
3- Whats meaning of locked or unlocked mean, I thought this term is for phones only.
4-Is sim card must for Ipad or we can use internet and apps without sim.
Sorry some silly questions. But thanks for all helping hands in advance.