How much does it cost to upgrade iphone 4?

I'm thinking about upgrading iphone 4 8gb to a new iphone 6 thats coming out soon. I'm wondering how much that will cost. I've been having the iphone 4 for a bit now about almost 2 years now. Its verizon too give details so i can know.

Depends on your plan, but I Phone 6 prices are $299-$499

Go to Verizon.com Iphone 6 starts at $199 with a two year commitment for the 16GB version. There are lots of different pricing options, go to their website and look it up.