First I would find out the value by asking here on "Answers."
State the Make and Model. Then give a brief description of the condition of the gun. State if it is working or not (Does it hold air or C02.) Then give it some sort of ration like Poor, Fair, Good, Very Good or Excellent condition.
Then I would try "Gunsamarica" on the web or "Craigslist" on the web.
OKAY, What is your question?
A BB gun would be more powerful
Most all Walmarts sell BB guns
Check with stores that sell BB guns.
Most sporting good stores sell them. Or on the Web
It all depends on the country and location where you live
In the truest sense of the definition of "automatic", no a bb gun cannot be automatic. In function, however, a BB gun can be automatic. A good example would be the Drozd BB gun which fires full automatic, but used CO2 as the power source.
anywhere you want as long as it is two tone
If its a BB Gun, Then Yes.
Pretty much outside the scope of a hobbyist
They would be better than 14 BB gun.
I would suggest an AirSoft BB gun. Not a Paintball or steel BB gun. Unless you have someone who is familiar with firearms then I would get him a Daisy Buck BB rifle and an adult to teach him the respect and rules of handling the rifle. The "Daisy Buck" is designed as a starter BB rifle for youngsters.