Thinking about adding a tier (Patreon)

Ok, so I get asked for source photos all the time. Sometimes, people give me the ok to post their source photos but I never do as a general rule. I'm thinking about adding a tier where I share source photos that I have permission to share, sometimes whole sets of photos that maybe didn't get drawn. 

Does anyone on here have any interest in a tier like this? If so, what should the tier price be set at? I'll take any comments or PM's into account, let me know your thoughts!

Derek