Can anyone tell me if a Kawasaki 550 Special Edition would be okay to buy - it's 10 years old but has low mileage

Sure I can tell you.

If it runs [it has been started ever so often and doesn't smoke like a chimney] and asking price is about $300 - $800 USD yeah it's probably worth it.

I just checked out ebay and saw a running 1980 Kawasaki KZ550A with 12977 miles for $300. Use ebay to get price ranges.

If it has been sitting for a year or more the carbs will require rebuilds and would not be worth more than a few $100 USD, and I would not buy it without doing a compresion check on each cylinder.

The Kawasaki 550 was a good bike.

Has it been siting, check hoses, tires
for dry rott.Will she start? This bike
is a good First bike. Get the wires checked out. Good Luck!