I am not trying to cast aspersions on you personally, but the terms warrant a lot of caution.  You are relatively new to the community, you are not offering real escrow, and the minimum bid is MUCH lower than what other MR are going for.  That last part is counter-intuitive, but is a hallmark of many scams in the past. 

I think you can bury all doubt by simply agreeing to full escrow through John K., to be released on physical delivery.  It really is that simple.