I can't find the article right now, but it has already been determined that BC will be getting higher gas prices to subsidize the cost of the pipeline, at about $100million a year, for crude that is going to other markets.
Determined by who? All I've seen are articles from anti-pipeline advocates that it will increase gasoline costs, and pro-pipeline advocates that it will reduce them. Just like the jobs argument, those against the pipeline will seek to minimize any benefits and maximize any risks, while those in favor will seek to maximize the benefits and minimize the risks. The reality will end up somewhere in between.