You can get 8GB of DDR3 memory here for $39, I imagine the prices are even lower in the US and Canada. Like Antony says, I think memory usage is more important in mobile devices. My Galaxy Nexus has 1GB ram, so you're going to be a lot more concerned with memory use on a device like that.
Firefox is using 560MB ram here, with five windows and around 20 tabs open in total. That's not much at all, though I've seen the memory reach nearly 2GB before when I'm opening dozens of tabs at a time (usually while browsing eBay or Amazon

). With the prices so low, I have considered upgrading to 24GB ram. Perhaps it's best just to wait and upgrade my CPU and motherboard too, since I'm still on an older X58 board.
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