There are many factors that go into the overall cost of removing a tree : size, location, health, risk, overall shape, surrounding structures. Some trees may cost $150 dollars to remove from your home while others cost $5000. Here is an in depth article about why these prices vary from tree to tree.
Every tree is different so every price is different. Most tree services have a minimum price for a tree. So if you have a 10 feet tall Bradford Pear Tree you will probably get a minimum price. What that price is varies from company to company but is usually in the neighborhood of $150.
It may seem a little tedious, but there are many factors to think about when judging the size of a tree. The width of the trunk, the height of the tree, the width of the crown, and how crowded the crown is. Sometimes a 50 foot tree with a 1.5 foot diameter trunk will cost more than an 80 foot tree with a 2 foot diameter. This is because of the crown of the tree. Some trees grow many branches that overlap one another. This makes the job harder and more time consuming for the tree removal service.
The location of the tree is very important when factoring in the cost. A tree in the backyard will almost always be more expensive than the same tree in your front yard. It is harder to get equipment in a backyard. Maybe you have a fence with a small gate that debris has to carried through. The further away the tree is from where your tree service provider can bring their equipment, the farther the cost goes up.
The health of a tree factors in to cost sometimes. If the tree is in an area that cannot be accessed by a bucket truck or crane then the tree must be climbed. Dead trees are dangerous to climb and the more dangerous the work the more expensive it is to remove the tree.
The surrounding area of the tree is a big factor to assess when getting a quote to cut down a tree. If the tree is near and/or hanging over structures like your home, shed, patio, pool, driveway etc. then the tree must be cut down branch by branch using ropes to lower the limbs down. Obviously this takes time and the longer it takes to cut down a tree the higher the price will be.
Most tree services will execute a job with around 4 guys. One man climbing and performing the cutting down of the tree, 2 guys hauling debris to a place it can be processed and one man running the equipment(chipper, bobcat, dump truck). The average tree company will try to get around $200 - $300(depending on risk) per hour for his guys to be working on your tree. This money will cover his labor fees, gas fees, dump fees, and general overhead(liability for the business, insurance on the trucks, maintenance for his heavy equipment, advertising for his business, taxes, etc.) This may seem expensive but you might be suprised at how much an efficient, well run tree service can accomplish in an hour.