Sorry, but your question HAS no answer- sort of like "What is a car worth?" Depends on the car, and it depends on the gun. Value of any gun is based on exact make, model, and condition. Being given none of the 3 items we need, we can't even make a wild guess.
Yes, flintlock type
Mainly flintlock smoothbore muskets, with a few flintlock rifles. There were also flintlock pistols and "fowling pieces"- shotguns.
Muzzleloading flintlock muskets.
They had flintlock guns
Flintlock muskets
Flintlock muskets
As far as I know, not really much, unless they had interactions with Westerners by then which they will have access to flintlock rifles.
Matchlock and flintlock muskets and shotguns.
Guns The Evolution of Firearms - 2013 From the Flintlock to the Percussion Cap 1-2 was released on: USA: January 2013
As we know the flintlock today, the first was made in 1610 in France. There WERE earlier guns that used a flint sparking mechanism, such as the wheelock and the snaphaunce.
Most patriots were armed with the Flintlock musket.
You will have to seek a professional appraisal