Seems to have been deleted from the US store, except in the Refurb section.

There still is a page with:

One SL: The Ultimate Wireless Bookshelf Speaker | Sonos

but “Out of stock” inside.

Hmm...

But its not anywhere on this page:

https://www.sonos.com/en/shop/wireless-speakers

Maybe it’s because of their promotion “Save 25%” on their Web Shop. I hope because I wanted to buy it. 

If they stop this model… what to choose now…?

 The Era100 is the next generation replacement of the Sonos One. 

Unfortunately double price than SL… :-(

Don’t know your location.. but Bestbuy still has them and I would think there are several retailers with them. I don’t buy directly from Sonos because of shipping. 

Huh?  The Era 100 is $250 in the US.  the MSRP for the One SL was $175 when it was released, I believe.  I’m not sure what it’s price was last listed at.

edit: Best Buy has the One SL MSRP at $200 currently with a sale/discount to $160.

At my country the prices (after recalculating currency) is about $300 for Era 100 and $175 for One SL.

But basically, the Era is a speaker that is much different from the One SL, it is much larger, much more expensive, but strangely enough, and most importantly for me, it has no Ethernet at all.
Fortunately, I found SL at a local seller :-)

You can add Ethernet using a external module, for of course more money.