Cheap grinder? Opinions please.

[nuphoria]

And I mean cheap: http://www.aldi.co.uk/uk/html/offers/special_buys3_20948.htm?WT.mc_id=2011-09-30-10-31

£8.99 from Aldi.... I know, we're not talking gilded lilies here


Here's my thinking: I guess it's likely to be a simple abrasive disk of some kind so I was thinking it could serve as a grinding down tool before some proper sharpening and finishing goes on. Only for knackered blades, nothing speSmurfpillst. Is it likely to do more damage than good or do you think it's worth getting at that price? 

[Farmman]

I am not a fan of these types of sharpener. Nearly always leave a lip on the blade and only offer one angle. I am no expert sharpener but these are my findings form one a friend had.