I'm not sure you are on firm ground here legally. You can't be selling work you have done for your employer without getting something drawn up that allows that.
This might be different from district to district, though it's certainly a concern. I know that my last school district not only accepted, but help facilitate, my taking digitally created curriculum to another district when I changed jobs.
Edit: I also wondering if sharing vs selling makes a legal difference? If teachers cannot legally share curriculum materials then every single teacher in this country is breaking the law.