Drupal modules to help with user story Hey my team is planning on moving our current project to Drupal and we're looking for what modules would help with our current functionalities. Here's a user story for more insight:

"User 1 has an inventory of items. Each item has a certain number of "points" attached to it. User 2 desires an item from User 1's inventory and has the appropriate amount of points to give User 1 for the item. An transaction occurs in which the desired item from User 1's inventory is sold to User 2 and the corresponding amount of points for the item are deducted from User 2's total points and added to User 1's point total."

I'm thinking we might have to end up adding our own custom code but if anyone knows of a Drupal module or anything that would make things easier, that would be greatly appreciated.
While custom code seems to be good option to achieve the transaction of item ownership, User Points module may help in transaction of items.

In custom way I would have created item as content type with user reference field for item ownership, I would have turned on revision on item content type so to get detailed report of transfer of ownership and on every transaction of item would have updated the ownership field with new owner, maintaining the revisions. User Points module provides handy api's custom integration and it also provides rules integration which looks more robust system to expand user points in future also.