Sure, IRIX could run in 8-12 mb
if you turn off X. But that means no graphics and no browser. I don't mean to be rude, but have you ever actually used an SGI?
In 1996, the O2 started at about $6000, and listed for more: http://cgi.amazing.com/internet/faq-6.0.html
As for the Indy, see http://www.siliconbunny.com/mirrors/www.tc.umn.edu/dols0011/...
"At the beginning of its life, the Indy came standard with 16MB of RAM. IRIX 5.1, the first OS for the Indy, was the Windows NT 4.0 of Unices, magically able to, performance-wise, transform an R4000PC Indy with 16MB of RAM (the standard configuration) into a 386SX with a weird blue box.
SGI realized this and quickly upped the box to 32MB, at considerable cost. (As you may recall, 16MB of parity 70ns RAM was hardly cheap in 1993-1995.) Subsequent IRIX releases made huge improvements in memory usage."
But not enough improvements in time to beat back the PC, of course.
"The Indy packs a decent amount of power into a very small (16"x14"x3"), simple, and elegant package. The chassis is just three parts: The "tray," which is sheet metal; the power supply; and the skin, which is a one-piece plastic cover with a thin sheet of metal covering the bottom of it to meet FCC compliance. The steel tray occupies the entire depth of the Indy, but not the entire width; four inches or so of the left side belong to the power supply, which occupies the entire depth of the tray and is a separate box. The whole unit is, although well-built, very economical and, dare I say, cheap. Speaking as someone who has had an opened-up broken Indy sitting on his basement floor, this is not a machine that screams "I cost $10,000." It's obvious SGI made a darn nice profit off these buggers."