Total damage: search for 2014 prices for replacement value

After a long fight with HDI insurance and assessment procedures, it is now recognized after 3 1/2 years that my casco damage is a total damage. However, it is now difficult to determine the replacement value, because the prices of 2014 would be important in the second-hand residential car trade. Who can help me to charge such prices: it is about a fully integrated motorhome LMC 6905I, EZ 2006, KM 85000 on the basis of the 4-to Mercedes-Sprinter 906, Zwillensbe maturation and differential lock, 416 CDI with 156 hp, with Alde hot water floor heating, additional diesel floor heating, as well as electric heating LMC, air suspension rear, coupling, motorcycle platform, Christop-SAT system, solar system, well-kept vehicle. Who can tell me from a reliable source about prices that were required for comparable vehicles in 2014?