Hardened Steel Anvil (100lbs or heavier) with at least one horn
Really crucial metalworking tool for metal sculpture, forging, and many jewelry applications.
The prices can be highly variable, but they tend to be $5-9/pound new, and about $3-5/pound used.
Also: we don't *need* a forge for an anvil to be an incredibly useful, meaningful addition to our metalworking capabilities. It has enormous use in many other metalworking capacities.