I own 2 bikes and have been riding seriously since 2010. In that time I've done 5 tours totaling over 17,000 miles. I also ride to/from work and other various places. Roughly 2,500 miles a year of "city" riding. In that time I've spent somewhere around $600 on parts/maintenance. +/- $100 I'd say.

This doesn't include any accessories I've added to my bike such as the rear rack, panniers, water bottle cages, lights etc.

With as many tires as y'all seem to be blowing through it makes me wonder where you're getting your tires? The paper mache factory?