Even though SFF PCs typically use smaller mini-ITX motherboards and SFF power supplies, their overall cost is generally higher than comparatively larger builds. This is due to the higher costs of mini-ITX boards and SFF power supplies, plus the additional costs of specialized power cables, cooling systems, fan grills, and more. Although you're achieving a more minimal aesthetic without sacrificing much performance, the SFF tax is a real thing that you need to be aware of.