Some will pay a premium for them, some won't. It's a personal preference. But yes to the right collector, they do enjoy toned coins.
"Beauty is in the eye of the beholder" Some people prefer blast white coins, and some people would kill for a toned coin. Toning is much of a close eyes and shoot kinda market, some will love that, and some won't. I personally like some forms of toning.This one, I would've paid a premium for if I weren't selling it for a friend: But just remember, not all toning is attractive.
You can classify me as one who doesn't pay premium for toned coins and usually doesn't seek them out either.
Please read the thread linked below, it should answer your question. Rainbow Toning's Effect on Price
Despite what you may think, most of the attractive toned coins out there are in Mint State. when a coin is circulated, the rubbing removes flow marks, and therefore luster. The chemicals that make attractive toning (AgS) need the little cracks and crevices found in flow marks to sit down and settle in. also, when a circulated coin gets covered in a thin layer of patina, also caused by silver sulfide this heavily inhibits further toning. For example, if this Washer was not uncirculated and lusterous, it would probably not be toned.
I am pretty sure when the OP said "mintstate" he was referring to an untoned coin that was basically in the same condition as if it was just minted. I don't think he was using it in the traditional sense of differentiating circulated from uncirculated. Having said that, circulated toners are cool as the other side of the pillow. I came so close to buying this SLQ many years ago. Wish I had!
True, circulated toned coins can be cool. Look at my avatar, its a Roman coin cleaned years ago, (like most ancients), but has retoned. To answer the OP question, I would say in US coins, and maybe some modern world coinage, toned coins can bring a premium. For ancients, toning can definitely bring a premium, but its different toning. Silver toning like posted here doesn't bring a premium, but hard green patina definitely increases its value. For all series, it depends on how the toning makes a coin more attractive or not, and general agreement on that attractiveness. If it doesn't make it more attractive to you, (like a lot of US toning nowadays to me), then don't pay the premium. Simple as that. I know I have a reputation of hating toning, but I don't. I love it. I have paid 3 times the price for a hard green patina toned ancient coin because to me it was beautiful, and back when toning wasn't a premium on US coins I bought tons of them I found attractive. Buy and pay for what you love, and for no other reason. Its your hobby, you are in the drivers seat.
It's worth more only to the collectors who like toning. Certain toning will multiply the price of a coin by multiples. Take a monster toned coin for example, a blast white coin may sell for x amount of dollars. But the monster toned one might sell for x multiplied 5 times. It all depends on the color + the collector.
