IMHO the graph is vague. I find that depending what you level of skill sets and how needed they are for certain applications, you can get nice renumeration. I've put out offers on some specialised IT skillset as competitive as out East before. Some 'big' companies here are EA, Telus and soon to be Microsoft. I've worked with some large IT firms in Ontario and have yet to see a nicer campus than EA Games.
In BC, I feel salary takes a bit of a back seat in return for quality of life. Its a bit more laid back here. So it depends on what you want in life.
I highly recommend that you first rent here as real estate prices is at its peak (well we've said that for the last few years now...). Even far flung suburbs like Langley or Mission has higher price than the say Milton or Ajax. So rent a while and get the lay of the land before making any decision.