I wouldn't be too sure about the dollar and gun criteria. Every state is different. It appears a felony is whatever the legislature defines it to be. Penalty is also whatever the law says.

Here's a quote from a recent web post.

"Under a recent change to the Nevada felony laws, deer poaching, or hunting out of season, is a felony punishable by up to 3 years in jail. While many of us agree that it’s not good to violate the hunting regulations, it does seem strange that poaching carries such stiff penalties, while the first two convictions for drunk driving are misdemeanors.

Such oddities are not limited to Nevada felony laws. In Arizona, it’s a felony to aimlessly fire a gun into the air in celebration. In Alabama, it’s a felony to pass a stopped school bus, even if there is no traffic accident and no one is injured. In Washington, a new state law makes it a felony to participate in an online poker game. In Illinois, possession of 1 oz. of marijuana is a felony, while in Alaska, possession of up to 1 oz of marijuana in your home is not even a misdemeanor – it’s not against the law at all. A proposed law in Florida would make it a felony for employers to ban guns in the workplace. In Arkansas, it’s a felony to excavate or display human remains, even for historical or educational purposes in a museum. In both West Virginia and Missouri, it is a felony to teach a bear to wrestle.

In ancient times, felonies were punishable by death or dismemberment, and forfeiture of all property. Originally, felonies were limited to only the most serious of crimes: murder, rape, and child molestation. Less serious offenses were misdemeanors. Today, many crimes have been promoted to felony status. In various states, felony offenses include aggravated assault, battery, arson, burglary, drug possession or distribution, embezzlement, treason, espionage and racketeering. Many of these crimes also have misdemeanor versions. Fortunately, penalties have been reduced as well, although virtually all felonies carry a minimum sentence of one year in a state or federal penitentiary."

Personally, I think finger chopping is an appropriate punishment for roulette thieves [g].