3D printing charges are based on the time it takes to print an item. The first hour of printing is free. Each additional hour will cost $1.00. For instance, an eight hour job will cost you $7.00. We can give you an estimate of how long your object will take to print.
There are several 3D editors you can use to create or modify 3D models for printing. Here are four suggestions that are all free to use (the first one is web-based and the next three are for download):