I purchased a trans from a member here that I won't be using. I have found out that my current trans is good and has LSD, so this one is going for sale. It is a newly rebuilt German Thomas 911/01 with what I am told are 914/6 gears. A-Ga-O-V-Za. My question to the experts is what's the value. Thank you in advance.

What is the tranny number?
If it is a 914/6 case it will have more value

If you don't know for sure what's in it, then it's much harder to sell for top dollar. The only data point you have is what you paid for it. It's at least worth that much.

You're selling a guess-box if you don't know what gears are in it (with absolute certainty) and how many new synchros and how many new dog teeth and how many new sliders. These are all extremely important questions when selling a 'rebuilt' transmission. Thomas does great work, but that doesn't mean the new buyer can assume that everything inside is new and perfect. Most times it's not the mechanic, but the customer who dictates what kind of work is done.