Excuse me for being naive. I am bit surprised why you would sell at $40.
By BB or BR acceptance ratio. Out of 5 to 6 names submitted ...1 gets accepted. So with reg fees of about $7 thats $40. Thats almost $0 profit.
- Leopard
Before you buy a domain for reselling --- Go to NameBio.com and see if similar names with same keywords have sold, for what price, which extensions and how recently such names have sold... As a beginner i would only stick to .com domains and i would avoid hyphens and long names.