A) Charge users to access the list of products sounds like a nonsense to me. Like, pay money to then spend more money?:) It could be fun if you could make a bundle of products made in WIP and sell it on single subscription model, similar to the project (don't remember the name) that sells subscription to Mac apps using same approach. A lot of work to be done to make deals with makers and to somehow make the positive ROI (not sure if possible) but something to consider. Good luck.