Guzzipurchase used…

Hello Guzzisti ́s, I don ́t belong to it, but think about buying a Guzzi 1200 sport at the moment. Budget is only enough for a used one, but I would like to take a 4V. What should be taken into account when buying a used one? Are mileage performances more important than years? Were there year of construction dependent errors? Are there concerns with machines with “motor tuning”? Are there typical problems that could have been avoided with care? f anything too? Which tyres are good or not at all suitable? My dealer buys nothing with more than 15tkm, why could that be so? Is Guzzi not comparable to BMW? Thanks for a quick feedback. The Guzzi is a real character bike on the motorcycle market.