That's certainly true alright, Ivan!
One of my buds here in L.A. has a three-car garage full of classic bikes, about a dozen in total, which basically span the years of manufacture from 1954 to 1979. Most were originally purchased by him within the last dozen years, and the average purchase of each bike in his collection was probably around $5000.00.
Among them (which BTW were in 95 to 98 point condition when he purchased them, based on classic motorcycle show competition criteria, and are all now restored to near 100 point condition) are a 1969 Triumph Bonneville, a 1969 BSA Rocket III, a 1975 Norton Commando, a 1970 Honda CB750, a 1974 Kawasaki Z1 900, a 1974 Moto Guzzi V7 Sport, a 1979 Honda CBX, a 1954 Harley FLH(this one being the the exception as to that "average purchase price of $5000.00...I think it cost him about $13,000, 5 years ago)....BUT, the point here IS that each of those beautiful machines he owns are now probably worth somewhere between 150% to maybe even more than 200% of his original purchase price for them.