It depends on the phone you want to get. Go to verizonwireless.com and log into your account. They should give you a full list of all the discounted phones you can choose from.
You get up to $100 off a new phone for your primary line. If the phone is cheaper than $100 then is free to you. If it is $129.99 then you pay $29.99 plus applicable local and state taxes.