Something I would love to see in Sansar is a way to enable even the newest, laziest, or most confused new user to own their own piece of the virtual world. The easiest way to do that, I feel, is to enable them to purchase prefabricated, completed scenes from the store, which they can then decorate or modify to their heart's content.
To do that, I propose...
1. Allow sales of full scenes which display on the "choose starting content" drop down menu
You've already given us the first step here. Enable creators to sell completed scenes on the store, which will then display on the drop down menu when the purchasing user creates a new experience.
2. Assets included in a scene which are made by other creators can be automatically purchased from the original creator as part of the scene purchase
When creating a scene, as an individual, you don't want to be limited to having to create each and every asset in your scene yourself. You can make amazing things when you collaborate! I propose that you encourage this collaboration by creating a "branch" style marketplace, wherein assets included in your scene which were not created by you will be charged to the original creator's marketplace.
When the scene is packaged, each asset included that is not created by you will be added to the cost of the completed scene. The end user, when buying the scene, would bulk purchase each of these assets from the original creator's store and have it added to their inventory, like normal.
If the buyer already owns an asset, that asset would not be charged.
When the creator of the scene publishes their scene, they should receive a popup notification detailing the cost of each asset included, so that they can balance cost on the fly; if they have used too many assets and driven up the price of their scene more than they feel is appropriate, they can find and remove some assets before final packaging.
4. Freeze market cost of assets at the time that a scene is published
To prevent people from unfairly gaming the system by driving up the cost of assets they notice are frequently used (e.g. charging 99,999 for a tree that was previously 100), market costs of each asset could be frozen at the time that the scene creator publishes their scene to the store. Alternatively, prices could optionally be capped at that cost instead of frozen, so that if the original creator decides to reduce the cost of an asset, purchasers can buy at the new reduced cost.
This idea of the branch marketplace could later be applied to things besides scenes - for instance, rextextures of clothing, similar to what you might see on IMVU.