I have bought all three that you and mrsD have mentioned. It is difficult to choose sometimes.

I have found that a lot of the Now have been on sale recently at the vitamin supply place I use. I can't get Methylcobalamine in Australia so I buy from the US. I usually buy the Natural Factors in the larger dose and split the tab in 1/2. I do that purely for cost purposes. It may not be of superior quality, I really don't know.

I figure if I'm getting that overseas I may as well get everything overseas (I buy Lemon balm leaf tea and essential oils and such) and then I get free shipping.