Rampage:
How can they want £17 for postage to them when your posting it?
That'll be because they are arranging the pick up
They're employing someone to do the admin of another arranged pick up, Purchase Order and putting it through their accounts, and paying for the insurance, instead of the OP.
If the OP wants save a few quid by doing their own shipping, and arrange a pick up when it's ready, then I'm sure Argos would be more than happy to let them do the work and take the responsibility. You can't expect a specialist commercial company to do the work of arranging shipping both ways at the simple minimum cost of shipping.
It's the same as an LBS being put out of business by Wiggle and CRC. Wiggle won't service a bike, give you advice, or know anything about bikes older than last year. They only make profit from undercutting prices on the bikes and parts (they sell huge amounts at approximately 3% over trade price), then people complain when the LBS puts its servicing prices up to make a living from servicing stuff that wasn't bought from them in the first place.
we dont charge for arranging pickup it's what the couriers charge us. we do give the customer the option to use their own courier service i.e parcel force etc
If the framebuilders and engineers can't make a reasonable profit from the work they do for us, they will die out completely and nobody will do this sort of work.
Either invest in the time, effort, tooling and money doing it yourself or pay for a professional, but don't bitch about the cost.
All the best,