The college rentals have been pretty flat for the most part, but the cost of entry keeps rising in that sector, so the better returns will most likely be in the frenship or cooper school districts

What economic sectors employ the most people?  

So with access to industry knowledge in Oil and gas and a growing competence in real estate investing you'll be uniquely positioned to move in and out of the energy and real estate sectors at opportune moments and do it tax deferred through 1031 exchanges. 

However in the residential sector some people think it’s reasonable to give a contractor 30k upfront on a 60k contract.

For instance, in Lansing, MI, the Sparrow Hospital just finished building a multimillion dollar Cancer Center (and, if not a hospital improvement then perhaps a new University building).So, think about similar buildings being planned by major players in the City's and County's stronger economic sectors, and ask yourself "if I'd been aware of it ahead of time, might I have been able to score a few cheap houses or strip malls and been able to flip them to the new, highly-paid employees of the Center or to businesses trying to sell to those consumers?"

This creates the domino effect where the pressure from the guys above you coming into your market/sector/deal size cause you to reach down smaller/further out, rinse and repeat all the way down to single family flipper and investors.

The Story I moved to Calgary four years ago for a job in the Energy sector after finishing my university degree.

It's not like the energy sector in Houston or natural resources as much as it's about a cool city.

Depending on your experience you could look into:Finance sector - residential and commercial loans, hard money, etc. 

Huge job growth with extremely stable economy (government and university largest employers) with medical sector about to explode here and of course tech is booming as well.  11th largest city in the nation and predicted to double in size within 20 years.