Hey, I have alto saxophone Highclass V.Kohlert s Söhne Graslite what looks exactly same as this one
and I have mouthpiece like this one http://www.saxophone.org/museum/mouthpieces/specimen/470
They are both in really good condition and play really nice sound
My question is about how much they are worth?
I think if you read Grant's answer to that question you will get a good idea of what you have and I don't have anything to add or subtract. It's value is a bit tricky as Kolherts are not as common as some other brands, thus not as desirable. Not saying its not a great horn just not as well known as say Conn, Selmer, Martin, Buescher, etc.
So that will lower it's value. I would place it max around $1000 U.S. but you may have difficulty finding a buyer you may be able to sell for anywhere from $500 to $1000 just depending on the market.
The mouthpiece is a bit tricker, as this is a single ring Otto Link it was one of the last made in Florida, but I belive they were finished in Elkhart when the company moved there. The value of these vary greatly. I would place it between $300 to $800 US as the condition of the piece will determine if any work needs to be done.
Hope this helps.