The Iomega one is a tenner more for 1TB in their stores. Expandable was not really part of the original plan, it is just that the larger versions they sell are either out of stock locally (yes, I guess I could buy online) or more than I want to spend at the moment. From what I gather, anything more elaborate or higher spec (such as with spare bays) is also adding to the cost and 1TB might prove to be enough.
I am not new to PCs by any stretch but this is the first time I am considering dabbling in network hard drives and the Iomega one seems like one of the cheaper options that also offers some measure of expandability. Besides, I might give the print server functionality a try. It does sometimes prove to be a pain having to keep my main PC on when I want to print over the network and I cannot be bothered with getting a WiFi printer just yet.
Of course, I am open to suggestions for alternatives.