Given the nature of technology these days, with the ready available of grid power, next day shipping, and wide variety of information on demand, it's easier to

Given the nature of technology these days, with the ready available of grid power, next day shipping, and wide variety of information on demand, it's easier to describe the limits to what can be made. Obviously - illegal stuff. Anything bigger than about 8 foot in length, or more than 1000kg in mass. If you can pick it up solo, you might be able to build it. Machining wise, you can buy tools to measure down to a micron, and harbor freight has stuff to get you to 25 microns. Used machine tools are widely available. Integrated circuits are outside your time and dollar budget. But Sam Zeloof could give you pointers. It's an amazing time to be a maker!