In brief: You can no longer buy Pixel 2 series phones from Google. It has quietly removed the standard and XL models from the store leaving only the Pixel 3. Pixel 2s are still available from several third-party vendors.
The Pixel 2 or the Pixel 2 XL are no longer listed in the Google Store. Android Police initially noticed that the Pixel 2 listing was redirecting to the Pixel 3 page. A quick check in the store confirms that the Pixel 2 is no longer available.
The only mention of the phone anymore is on the comparison page where it still compares all three iterations of the device. However, only the Pixel 3 has a buy button. All that is left on the Google Store phone section is the Pixel 3 and accessories.
The disappearance was foreshadowed by discounts on Pixel 2 and XL in February of $100 and $250 respectively.
Even though the Pixel 2 only launched less than two years ago, the discontinuance is not unusual for Google. It stopped selling the Pixel shortly after introducing Pixel 2 as well. That doesn't make it any less a shame. The Pixel 2 is a good phone.
This leaves Google without an entry-level phone in its store. Fortunately for those looking to buy one, Verizon still has them as do several third-party vendors including Best Buy. Amazon has refurbished Pixel 2s starting at about $315 and new ones for $560.
Google is offering the Pixel 3 as low as $450 with the trade-in of an eligible iPhone. Otherwise, you are looking at at least $800 for its newest flagship.