Allow the ability to browse other collections while allowing collectors to select items in their collection to "taking offers"

Let me make sure I understand.  A user wants Mario Kart 64.  They don't see any for sale in the marketplace.  They can then find other collectors who have that item in their collection and make them an offer.  If the owner accepted then a sale could be created on the site between the buyer and seller?

i would also like to see this feature added to your robust set of buying/selling tools. I don't consider it too obtrusive, as it is only allowing offers to be made to persons who perhaps never considered selling their items due to inexperience with online selling or unaware of desirability of an item-as value is sometimes determined by factors other than market demand, such as sentimental value, etc. The worst that can happen is the owner can say No, and no sale transpires, and that is that-all one can do is ask, right? But if they are amenable to selling, then best case scenario is you end up with the item of your dreams that you have been searching for ages for! How good is that?! Along the same lines, how about a way to browse the wishlists of others, to see what's trending/most wanted or to just see if there's anybody looking for something I got. Maybe make a window for the looking party to indicate what they would be willing to pay for said item? Final selling price would be negotiated between them and anybody replying to that item. I'm sure this idea needs more consideration and discussion before going live, but something along those lines...thanks for all your hard work, you guys are doing a great job!!!