At its core, surprisingly little: two towers that each move in X (depth) and Y (height), a length of resistance wire stretched between them under tension, a way to heat that wire, motion hardware (steppers, belts or screws, guides), a controller, and power supplies for the motors and the wire.
A simple 2-axis cutter can be a fixed bow with one moving table; a 4-axis cutter gives each end its own X/Y so you can taper and twist. Budget a weekend or two, basic hand tools, and a willingness to square things carefully. The wire and its tension matter more than fancy frames — a rigid, square, well-tensioned wire is 80% of a good cut.
A simple 2-axis cutter can be a fixed bow with one moving table; a 4-axis cutter gives each end its own X/Y so you can taper and twist. Budget a weekend or two, basic hand tools, and a willingness to square things carefully. The wire and its tension matter more than fancy frames — a rigid, square, well-tensioned wire is 80% of a good cut.