Oil doesn't really have an alternative right now for many of its applications. Plus, at the beginning of the pandemic gas was dirt cheap, yet no one needed it. However, this discussion was about transportation of oil, and the idea is that pipelines are more efficient than rail or trucks (if that even makes sense), so it's a pity the decision to halt the project is more political than even environmental.
Increasing the price only needs to reduce usage in any areas to see a net benefit.
As to transportation options, boats and trains are extremely efficient to the point where pipelines don’t make that big of an environmental difference.
According to [1] the cost in 2018 was $5/barrel via pipeline, vs $10-$15/barrel by train. Also, for Alberta boats are not an option since it's a landlocked province. Also, Alberta's oil sands are the world's largest oil reserves after Venezuela and Saudi Arabia, so a pipeline would be very economical once it starts running.
Also, quote from [2]:
While long-haul oil and gas pipelines are also more economical and environmentally friendly than other modes of transport like rail or trucking (pipelines create 61 to 77% less greenhouse gas emissions than rail when moving crude over long distances, says one recent study), they also have a safe delivery rate of greater than 99.999%.
This is quoted from Enbridge's website, which is a pipeline company, which may be a bit biased, however I doubt they are lying.
As you guessed the source is biased. The question isn’t if pipelines are more efficient in use, the question is if the construction of pipelines + operation of pipelines over their lifespan is a significant net environmental savings. And that’s both much closer and largely irrelevant vs the environmental cost of the oil shipped via the pipelines.
As to being lower cost, again the lower cost isn’t a savings for the environment it’s a savings for the oil company.
