As I said:
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
However, if I was Argos, arranging a pick up of someone's frame, it would have to be fully insured, at full replacement value. Any damage, previous, fictitious, or actually incurred during shipping, could be claimed as Argos' liability by the customer. In this case, I would want to insure the incoming and outgoing shipments for at least £500 to cover any eventualities, especially given that, one way at least, it is being packed by the customer and picked up blind. My couriers (TNT & DHL generally) only cover stuff to a declared value of £50 within the basic shipping cost. £500 cover would cost an additional £15 each way at least. Company 'Goods In Transit' might cover any loss or claim, but with a typical excess of £150-£300 on a business policy, it's not worth losing your no claims, or risking a visit to the small claims court and an unproductive day away from work. So, the customer pays the extra cost, or sends it themselves at their own risk.
Time involved..."5 minutes to arrange the courier, 15 minutes to pack the frame". Yes, true but also: another entry in the accounts, another line on the courier's invoice to check against the purchase order raised, check they haven't over charged you or volumised it at the depot, new shipping box and packing, label printing, Docs Enclosed envelope, another delivery to track, another email to send the tracking number to the customer, taking photographs to prove the condition of packaging and frame on arrival and departure, chasing the couriers when they haven't picked up, being nice by listening to the miserable driver, letting him use the toilet, watching him throw the box into the van :evil: ...it all adds up.
All usually non-billable time, at a cost to the company which wouldn't be incurred if the customer brought the frame into the shop and took it away again when the job was done, or arranged their own shipping. They are being asked to pay for an additional service...hardly "a hidden charge".
Given that the average UK company overhead per hour/per employee* is close to £20/hour+wages, charging £17 to cover your customer's arse and do all the work for them doesn't sound that bad to me.
That'll do...it's up to the OP.
All the best,
(*ref: ONS 2007: average annual overhead cost per employee £23,244/1200 productive hours per year = £19.37 per hour+wages)