The encore is heavier duty and can handle larger loads, but doesn't do rimfire (the contender will).
The first rifle should run you between 550 and 600. I got a stainless in .308 for $560. You can get them through Walmart too (if you don't want to mail order and deal with FFL).
Extra Barrels will run about $250. Not all forearms are interchangable. There are forearms for Blackpowder, Standard Rifles, Bull Barrels, and pistol configuration. The synthetic ones run about $30.
To me, the interchangable barrels are the biggest selling point of the Encore. Once you have the reciver, you can order barrels in the mail and not have to deal with FFL at all. That's a huge selling point to me.