I think the crux of this whole issue is whether or not "free for credit" is really a lowball bid. Let's say I've narrowed my search for sunset pictures down to 3 choices. One is CC licensed. One is public domain. One is priced at $6,000. When 2 out of my 3 options cost $0, then $0 should not be considered a lowball bid. It is a realistic bid based on market conditions.