Alaskayorkie has given great advice. I also think one of the cost factors are the area you are purchasing from. In my area, $1500 for one is the highest I have seen. But I also have seen them as low as $100. Usually from a puppy mill.
. Listen to Alaskayorkies advice. Do your research. Just noticed you are from Oklahoma. Watch for puppy mills. They are common in both our areas.