Probably everyone else has already realised this but...
If you visit the Homebase website you get pretty much the Argos search box and the the equivalent list of argos products at the Argos price.
However if you buy through the Homebase site you can use the Homebase 'Spend and Save' card at check out which offers up to 10% cash back (as homebase vouchers). Unfortunately these currently have to be redemed instore at Homebase but the FAQs report online acceptance coming soon.
Hope this helps