Q: Is there any chance that I can swap my ipad2 to ipad air?then how much will it cost?

If you are in the U.S., Apple offers a recycle program where they will give you an Apple gift card for your device.

You can estimate its value here:

http://www.apple.com/recycling/gift-card/

Anyway, regardless of how you accomplish selling your iPad 2, you would sell it and independently buy a new iPad.

Denec wrote:

 

Is there any chance that I can swap my ipad2 to ipad air?

No.

How much will it cost?

Full price.

You can "recycle" it thru Apple and get an Apple store gift card you can use towards a new iPad.

See this -> http://store.apple.com/us/browse/reuse_and_recycle

Let not forget the iPad 2 is still being sold, how old is the iPad 2?

If you just bought it Apple does have a 14 day return policy where you could return it and get the iPad Air for the difference of their prices. If it is after the 14 day limit then your only options are as mentioned above.