For a standard storage shed, a gravel pad or concrete blocks will serve you well at a fraction of the cost. A slab is overkill in most cases.
Where a slab makes sense is for larger garages, workshops, or buildings where you're doing heavy work inside. If you're rolling vehicles in and out, running power tools, or using the building as a serious workspace, the flat, permanent surface of a concrete slab is hard to beat. It's a bigger investment upfront, but it turns your building into a permanent, heavy-duty structure.
