Oh dear. If I start buying all the new toys I would like to buy I would have to add onto my house.
Maybe I ought to start buying lottery tickets.
The tech is NOT expensive, believe it or not.
Ender 3 is $199
Ender 3 V2 is $269 (brand new, upgrade from Pro version with many improvements)
Anycubic Photon is $169 (sale) (higher resolution resin printer, needs ventilation)
It'll take about an hour to assemble the first two, and then the key is to keeping it level/calibrated. If you keep it level, it will print with great quality. It comes with all the tools needed.
The PLA material is also very inexpensive. A roll of PLA is about $20-$22 average, and will last a LONG time. It comes in many colors. You can use the item as soon as it is done printing.
For the resin printer, it costs about $20 for a 500ml bottle, which will do quite a few prints. (but still much more expensive than PLA and light sensitive) The material is a bit toxic and you have to give the resin items a rinse in a pool of alcohol, and then they have to be "cured" with uv light. But the result is superior to PLA.
The *.stl files are created/drawn basically in a cad type program, with many choices available. You can also grab these pre-made from MANY websites, such as thingiverse.com If you find your missing light piece thing on there, let me know.
Then you run that *.stl file through another program, called a SLICER, which lets you lay out how many you want to place on the bed of your specific printer. The slicer lets you customize it with the parameters specific to your printer (bed size/print area, temperature, if supports are needed, speed, quality level, etc) The slicer exports the result as a *.gcode file, which the printer will directly open.