We've made the point in other contexts that while Aldi is good value, it isn't always cheaper than its competitors. The same holds here.
Yes, this is a better deal than the requiring-power-supply drive that Aldi had for a similar price last year. However, a quick search on StaticIce reveals a lot of similarly priced offers. The main distinguishing feature for the Aldi offering is USB 3.0, which is a good choice if your laptop or PC is one of the relatively rare models which supports it, but won't make any practical difference otherwise.