At present, AirPort Express, AirPort Extreme, and Time Capsule are not available.
A year ago, Apple shut down the production of an AirPort branded router. Now the company has stopped selling it: this applies to online and offline stores.
Currently, in some countries, only restored gadgets are available, but not for the long term. As such, Apple rejects AirPort Express, AirPort Extreme and Time Capsule.
Remember, AirPort Express hasn't been updated for six years, and AirPort Extreme and Time Capsule – five years. AirPort Express can be bought for 99 dollars, Extreme – for 199 dollars, Time Capsule – for 299 dollars.