Well, like so many other things, it's field-dependent. :-)
If you're working in software, you don't even need a garage: a dorm room or studio apartment, a laptop, and a few thousand dollars to pay for web hosting, will fill your need for physical equipment. I think that one of the great achievements of the past few decades has been the invention of an entire field of technical endeavor in which the base costs are so low.
But not all innovation is in software, and it's good to get a reminder that most fields have substantial equipment materials and equipment costs. A lab doing electronics, biotechnology, energy research, and many other totally necessary things has much higher requirements.
When I was doing microfluidics work in grad school, I was doing some of the cheapest microfabrication research out there. All I needed was a continuous supply of photoresist ($800/L), some decent-quality silicon wafers ($200/pk of 20), access to a high-resolution transparency printer for masks ($150/print), silicone plastic for making devices ($50/lb), and a good fluorescence microscope ($50,000 or so). Oh, and access to a clean room with about $1,000,000 worth of equipment, but that was shared and I don't know what our "rent" for access was...
Edit: costs estimated from the Internet and 2yr-old memories, but I think they're pretty close.
If you're working in software, you don't even need a garage: a dorm room or studio apartment, a laptop, and a few thousand dollars to pay for web hosting, will fill your need for physical equipment. I think that one of the great achievements of the past few decades has been the invention of an entire field of technical endeavor in which the base costs are so low.
But not all innovation is in software, and it's good to get a reminder that most fields have substantial equipment materials and equipment costs. A lab doing electronics, biotechnology, energy research, and many other totally necessary things has much higher requirements.
When I was doing microfluidics work in grad school, I was doing some of the cheapest microfabrication research out there. All I needed was a continuous supply of photoresist ($800/L), some decent-quality silicon wafers ($200/pk of 20), access to a high-resolution transparency printer for masks ($150/print), silicone plastic for making devices ($50/lb), and a good fluorescence microscope ($50,000 or so). Oh, and access to a clean room with about $1,000,000 worth of equipment, but that was shared and I don't know what our "rent" for access was...
Edit: costs estimated from the Internet and 2yr-old memories, but I think they're pretty close.