Scan is my favourite tech etailer, I regularly trawl the Today Only section for deals.
The 1GB is generally worth getting over the 768MB. Especially considering the price.
Edit: Oh, and even though it's in the Today Only section, as long as you keep that link then the deal works for about a week.
Edit2: Another piece of advice, try to buy everything from the same etailer, it saves on shipping costs.