Cost of living can absolutely be calculated and compared between any two cities a hockey team resides in. Endorsement opportunities not being mentioned in contract negotiations would be a huge surprise for me, especially since these opportunities directly involve the team more often than not. It's not an "off chance" they get endorsements, it's negotiated beforehand.
Quality of life, while not necessarily objectively measurable, is certainly a factor and it's something a city like Toronto has in spades over a place like Columbus or Arizona. Toronto, Vancouver, Montreal...these are all badass cities to live in where a guy in the 27-35 age range would have a ton of fun spending their money and being around a lot of attractive opportunities. So yes you'll pay more in taxes living in Chicago, LA, NY, Toronto, Seattle, etc...but you also get to live in a world-class city with millions of dollars and enjoy these benefits other cities may not be able to offer. Point being, it's a factor, it's an advantage some markets have over others. I