Price jump after trying to upgrade our TV and broadband bundle

Hi, I'm trying to move our current broadband-only package onto a TV and broadband bundle because the kids keep moaning about no live TV. The website showed one price, then when I got to the basket it was higher, and now my account page is showing something else again. Is that normal or has the bundle changed halfway through? I've not clicked final confirm because I'm wary of getting tied into the wrong thing. Existing customer, if that makes a difference.