That motorcycle appears to be very well cared for. Based on what I saw in your video, I would pay $2,000 for it without any hesitation.
One thing you need to be aware of: it is 21 years old. Some components - mostly the rubber ones - perish with time, not mileage. So you might need to do some maintenance over the wintertime (perhaps not this coming winter, but some year in the future) such as replacing coolant hoses, diaphragms in the carburetors, etc.
I have a 2001 ST 1100 and I have not yet had to replace any of these parts... but I am aware that if I want to have 100% reliable service from the bike, I should soon take it apart and proactively replace some of these things, rather than waiting until a problem develops.
Take a look at the date stamp that is on the tires. If the tires are more than 6 years old, you might want to consider replacing them, even if the tread appears satisfactory. You might also want to inquire when the brake and clutch fluids were last changed - if the fluids do not appear to be clear when you look at them through the sight glass, it might be prudent to bleed the systems and put new fluid in.
Michael