Reading through THIS , write-up, it seems straightforward.
Before the item sells you need to check on postage costs, you then decide how you want to send it, choose the rate paid ( this will be cheaper than PO or couriers because eBay is acting as an agent and getting cheaper rates by bulk, then letting you use them ). Put postage costs into the advert. Item sells. You then decide whether to take it to a collection centre, where you can get the label printed, if you don’t have a printer, or choose for it to be collected by a courier, ( you will need to print the label off yourself ) with a choice of courier options ( which ones in particular, I don’t know, but the Royal Mail is in there ).
eBay will make a profit on your postage, but you will also be getting it cheaper than direct from PO, RM or courier.
Doesn’t seem to be a bad idea at all, but then I’ve sold very little on eBay.
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