Last time I tried to send a laptop it was £20.
The time I tried to send a PC, they said it was too heavy.
edit: I see what you mean though (http://www.royalmail.com/portal/rm/content1?catId=400031&mediaId=51000711 ), but when I have asked they have given me the choice of Special Delivery with some kind of insurance\cover, and normal first class (I suppose that's 'Standard Parcels' ?) with next no cover\insurance. I don't think I've ever been offered add-on insurance for an extra £3.50.
So I accept that within-UK parcels can be reasonable, provided you don't want tracking, insurance, next day, etc, but international parcels are still far too expensive. It was £60 to send some SCO Unix books to America, it costs more than the cost of a replacement hard drive to return a hard drive to Ireland, and just as much to return a faulty Iomega REV drive to the Netherlands.