Just joking.
BUt to your question....Kesslers are made either in Taiwan or China...there has been a lot of speculation as to this and internet sax people taking their best guesses.
Some say they come from the same factory as Chateau, a brand which has some repute and respect and are generally considered pretty good, although the number of people who own them or who have serviced them and have chimed in with their positive feedback are limited, relatively speaking.
The company and shop has a good reputation, generally. It seems their customer service is pretty good.
Now, I have back-perused some of those reviews and threads and discussions, and the reality, from what I have observed, is that Kessler himself has never stated that these come from the same factory as Chateau, matter of fact I have never found any solid comment from anyone at the brand (Kessler) that they are even Taiwanese.
This isn't unusual, a store brand with a subcontractor building their brand of horns isn't likely gonna publicly admit to who the subcontractor IS, right ?
So, again, that info and claim...has been generated by owners and a limited # of techs, not to be dismissed however. Former member (may he RIP) Saxoclese was a reputable tech, and he was pretty high on Chateaus as a brand which gives good bang for the buck; I am not certain he ever stated that a Kessler IS one, though. So again, I think making that connection...is dedbatable given what we know.
(Again if anyone can find me a thread or comment from the shop which states this connection clearly, I am all open to that).
Looking at it from the other end - I cannot say I have seen threads where someone stated "I bought a Kessler because they had a pretty good reputation but I am REALLY disappointed in this horn". Which is some yardstick there. Most reviews are relatively favorable.
On this side of the pond, they do have a decent reputation as a house brand which is relatively inexpensive if one is seeking a new horn and wants to get some quality out of it. It is sort of one of the "I want a solid new horn but cannot afford a new Yamaha or Jupiter or Buffet or Yani or Selmer or JK" etc....
Resale - they take a big hit. The slight mythology/uncertainty of what folks believe them to be, as far as factory origin...plus the fact that to many sax-seekers who know only the Big names this is an unknown/unfamiliar name...plus them having very little name recognition outside of US...means their resale values remain on the low side.
In the US a lightly-used one will sell online for around half of what they went for, new. Just as a gauge, just from what I have seen on eBay, Craigslist, FB Market, Reverb, etc.
Hope this helps a little. If you listed it for $1600, you may sell it relatively fast, the name at times has enough Cred developed to make people look at one. It won't sell in a day, but maybe within a couple weeks.
If you listed it for $2000ish my guess is it'd sit around for a while....because now you get into used Yani/Yamaha intermediate-pro range prices for a Tenor..... and that might be a hard argument to say "this Kessler is as good as a Yama 52/34/575/61/62 or a Yani 8XX or 9XX series". I don't think most used Sax seekers would make that leap of faith with their wallets...