Not a common date for toners, and this one comes with nice colors(pinks and greens), on both sides and vivid but not full covering and a lower grade. Toner experts did this morgan go for fair money? https://www.ebay.com/itm/202856776936?
Actually, if memory serves me well, while not exactly an 1881-S or 1883-O, the 1889 does come nicely toned with some frequency. Edit . . . I think way too much money was paid for this coin. If brought to my table and an offer was requested, I might be in the $200 range (no, I did not accidentally omit a decimal place!).
It's not the most common date with color but isn't the toughest either. It sold for $1,250 which is very strong money for an MS 62 with mid-high tier toning (likely a 4 on the 6 scale). I've bought, sold, and still have available better example for much less.
And that's market acceptable? I admit that I'm not one of those who's kept watch on individual Morgans for a century or so to make sure there were no shenanigans, but that kind of color on both sides seems a little suspicious to me...?
Yes it is market acceptable (PCGS said so ). The photos might exaggerate the color a bit but nothing about it looks off. Dual sided toners are less common but are found in albums, envelopes, and people's windowsills (don't forget to flip it over ).
Where do you see that? The link says it sold for $5596. In my opinion $1250 is absolutely ridiculous. If the link is correct, $5596 is absolutely Forrest Gump money. Its a very nice coin, and absolutely genuine, but it isn't worth 10x times list.