Where It Started
The idea of a 3d printer started in 1980 but was never commercialized. Three years later Charles Hull create the first SLA machine which shines a uv lazer at a secial liqid substance that would harden once exposed to it. It would draw pratterns layer by layer until the shape is complete. This functions similar to how a modern resin printer works by using a UV panel to draw the entire patern at once.
6 years later the first FDM printer is designed. The way it prints is by melting platic to a liquid state and then drawing the layer patterns through a moving nozzle. The plastic solidifies rapidly after being layed down, bonding itself to the rest of the model. Because of a patent, at this point the average price for a 3d printer is around $10,000. Its not until 2009 when that patent expires It drop below $1,000. After that, many companies form to explore this market to iterate on designs every year, improving over and over and lower the price even further. At the current day, theres a wide variety of printers to fit any budget. Depending on the max size you want, you could even by a printer below $100.