* A work of art that's appraised at $10,000, for example, but that's priced for sale at $5000, is not necessarily a bargain. As stated above, a retail or insurance appraisal can be many times the fair market value of a work of art. Always determine fair market value first, no matter how big a bargain the seller makes you think you're getting.
In general the aircraft must be at least 500 feet away from any person, vessel, vehicle, or structure. In congested areas the aircraft must stay 1000 feet above the highest obstacle within a 2000 foot radius of the aircraft. There are special rules for helicopters that allow them to fly closer than these general limits.
Non-pressurized aircraft can fly as long as the owner/operator wants to keep up with proper maintenance. Most commercial airlines will run their aircraft at least 6 days per week, and 48 weeks a year. (given an average of 4 weeks per year down for maintenance) If a long-haul 747 flies 6,000 miles per day, you can do the math.