Has anyone used the Dry Guy Boot Glove for insulation for cold weather ice climbing/ mountaineering? Here's the link: dryguy.net/BootGlove.html
They are designed for ski boots, but I can't see why they wouldn't work for ice boots. For $30 compared to $150 overboots, it seems like a better deal for when you need just a bit more insulation.

I just vapor lock my feet in grocery store plastic bags, over thin layer of polypro socks, with thick wool mix socks over that. Seems to work for ice climbing very well.