While my parents' house was being remodeled, I designed a garden shed for my mom. Enough money was being spent on the house and my parents are fans of used things with fun stories, so I tracked down leftover, scrapped, and used materials for each component. The total material cost was about $300.
The items I tracked down include used metal roofing from a re-roofing of my father's business, used wood siding from a tear-down of a friend's barn, wood windows and the front door my mother saved from her first home, a skylight from the builder's scrap heap, and an unused, large, vinyl window from a salvage shop. The concrete foundation was originally built for a playhouse that was torn down by the previous owners of the house.
This barn wood plank has a hole patched with a coffee can lid.
Looking for additional utility on your property, like a shed or even a backyard cottage or Accessory Dwelling Unit?