My experience is that the out of memory problem is not directly linked to the available RAM a system has. It is related to the used OS too i would say.

I run Infinite on an Pentium 3 even with 256 MB Ram only. And render the scenes there i have created on my main system. Never had an oom there. It is slow, yes but it works. There i use still Windows 2000 Pro and never got those errors others have on Windows XP.

One day your ship comes in - but you're at the airport.