A quick Search Sitters in Calgary, AB without any additional filters to narrow the area or specific preferences resulted in 14 pages of house sitters (20/page except last one=over 280 sitters) and when I set the price range to 41+, only 4 pages plus 1 on the 5th page=81 house sitters charging more than $40 for house sitting.
If you want to increase your price, you need to consider what would set you apart or how you can promote yourself so clients will see the value and contact you.
Personally, I think a lot of sitters price too low for house sitting service, but then again not everyone provides the same level of attention. Some may stay there almost the entire time while others will be gone to walk other dogs, care for their own pets, go to school, work, etc. Some price it as an all inclusive service based on 24 hours and others opt to charge a la carte style, interpreting the hours as it fits their preferences and modifying it for additional walks.