When I had my QS a few years ago, I would get phone calls from Pattern designers asking if I would sell their patterns. I also had a couple of local gals that I sold patterns for. As to the phone calls, I would ask for 5 copies of their pattern and a letter of introduction to display with their pattern. This usually got good results, and it gave everyone, including myself, a chance to have a little history on the designer. I would pay the designer half on delivery and finish paying for the patterns in 30 days. It never took the 30 days, because I was always looking for more copies of the pattern within a week or two. I really believe the letter of introduction made the difference.
Good Luck on your venture!