Request for Advice on Questar 3.5

My family has a Questar Standard 3.5 being serviced by Questar as I write this post. Serial #1-1057. Questar told me I could sell it for $2,500-$3,000, then we discussed the fact that it was returned to Questar and modified to prevent vignetting when taking photos with a 35 mm camera. I was told it costs $1,900 to have that modification done today. I was told that all the items that would be expected by a buyer are present and accounted for, and he referred me to AstroMart for selling this scope. We will be further discussing its final value after servicing is complete. As I view prior sales, I don't see old 3.5's (without the stated modification) going for $2,500-$3,000 as indicated by Questar. Was I misinformed by Questar? Or is this a collectible item that has greater value than some of the other old 3.5's? Any information that would help me through this process would be greatly appreciated!

Crystal:

Let me welcome you to Astromart. This is certainly the place to not only get the information as to what your Questar is worth but to sell it as well. No website can be 100% secure but Astromart is the best I have seen when it comes to honest, friendly people and a secure, safe environment.

As far as the value, this is not an area I know much about but the people who do are here and will help you out.

Best

Jon Isaacs

Crystal: I would not presume to tell you what the "value" of your Questar might be, but I still have and use the 3.5-inch 1969 Questar that I bought when it was new, and the following information might he helpful:
1. Your serial number indicates that yours is a 1971 model, but it does not have the broad-band coatings and its mirror is not of the higher grade quality of glass that some Questars have.
2. Two years ago, I sold a 1971 3.5-inch Questar on Astromart, and I received the asking price. For details, see ad #579645 posted on August 12, 2008.
3. I am skeptical about the $1,900 upgrade you mention, but the standard Questar servicing that you are apparently obtaining is advisable for the older models, even though not inexpensive.
4. Astromart has a separate forum for "Questar and Quantum" telescopes where your inquiry might receive more knowledgeable attention.
Herbert Kraus