firstly don't worry no one is taking a pop but information is being offered
Kleins are very age and model related when it comes to values.
Upto about 95 some models fetch high prices(the mantra is not normally one of those) after 95 trek started sniffing around klein and after about 97(klein experts will confirm or correctly update as my memory is shady) kleins largely became treks with klein badges on and those fetch even less.
The carbon mantra isn't as rare as you may believe but I wonder if you had considered using a what is my xyz worth guesstimate threads
<----97 section http://www.retrobike.co.uk/forum/viewto ... start=3960
and the 98-----> onwards http://www.retrobike.co.uk/forum/viewto ... &start=255
Chap if I may ask you to consider one thing, you've come into a forum full of experience on prices, models, ages and market needs...if a number of people offer relevant advice and you don't like it because you think it's worth 3 times more than it is then I'm afraid we are never going to give you the advice you want to hear
It's a nice bike, someone will want it at a fair price, give the guesstimate links ago once you know what you have and I'm sure all will go well