The new 1kg satchels are regular post, not express. They're $109.50 for a pack of 10 and there's nothing to indicate they're not here to stay. AP was out of stock for several weeks so they're obviously a very popular product.

Some post offices are selling them separately for a slightly higher price. Not sure if it's allowed but they're doing it. I've already used 3 or 4 of my pack of 10.