2c.
I've had guzzis for almost 30 years now. Before that I had ducatis. I got online in 1990 and on ebay a couple of years after it launched. I watch prices closely all over the world, everywhere I can access ads.
It's your bike ask what you want, but you can't force a buyer to pay more than they will. Asking prices are irrelevant if the bike sits on market for months or years and never sells. This is the first mistake sellers make. I watch Last Advertised Price and where I can get it actual sale price. Sellers who never drop their prices annoy me because they just clutter the listings and waste my time, but that's the deal.
Occasionally there are a lot more buyers than sellers, like 750S/S3 atm. I know an S3 sold recently in australia for $35kAU. It was immaculate. Traditionally V7 sports have been worth more but so many have come in from the states the later bikes are getting bigger money. Supply/demand shifted. Same thing happened with disc brake eldoradoes about 10 years ago. However far more often it is in balance. Sure guzzis are relatively rare but that's because no one cares. Yep we love them but 90%of riders barely know what they are. T5's are rare, but no one cares.
Broadly speaking cars and bikes devalue for about 20 years then start to rise. The V11's are almost there. I'd say prices are flat with "normal"models around that $3500-$5000 in the USA. Concourse examples or particular bikes probably a bit more, scruffy less. This is the cheapest they will ever be. In 5 years they will be a lot dearer and rarer.
I'm looking for something in australia to just ride and not worry about. I joined this forum to find out more about the V11's which I quite like, but the few listed here are about double the money and I'm short as so now I'm looking for a jackal/stone/cali special.
I had an 1100 sport carb. The only time in my life I wished I had longer legs. I had to sell it, just fr too high. I still think they are the most beautiful bike guzzi ever built and incredible to ride.