Tried and tested :)
Just passing on a tip to help with delivery charges @ Tesco direct.
I noticed Free Delivery on selected Clearance home electricals.
Promotion ends: Monday 25 February 2008
And these are the cheapest item in this offer,just add them to your order and go to payment page and it will show you delivery charge of £4.95 removed,delivery is reduced to just the price of the bags.
As with the sim card method,just return if you don't need them......thus free delivery
Morphy Richards upright bags 5 pack @ £1.47
Catalogue number: 202-9465
Although not a lot in stock as a clearance item,might help somebody :)