Anyone selling a good quality double ski bag?

At £80/£90 return the cost compares favourably with the more expensive extra baggage airlines.

Compares favourably with ordinary courier prices too. Can see that being worthwhile, especially if you've got - for example - a herd of kids and bags to get through the airport anyway, or worries about fitting all your gear in the hire car / transfer bus. Very often there's a separate drop-off / collection for ski bags so you're saving extra time there too.

Like all things; if you can afford it, and it's useful, then it's good value!

Last time I moved skis to a resort used my brothers garden furniture umbrella cover. Place some clothes around your skis and good to go. Reality is after 1st hr your skis will have some cosmetic damage, so anything that protects edges and base is sufficient.