Bargain - the complete new key I got off ebay worked.
$95 key
$40 cutting blade
$50-60 coding at Skoda (not sure exactly because it was done with some other things).
$185-195 Total
ebay seller was tmc_car_keys
Item title
NEW SKODA REMOTE KEY 1K0959753G OCTAVIA, ROOMSTER (that part number matched my existing key)
My car is a 2008 Octavia Elegance 4x4. This has the version 4 immobiliser which needs to be done by Skoda (can't be done with VCDS as you can't get the codes you need )
Also getting a non electronic key for $40 from the locksmith.