Mmmm… wait, are you saying that you are buying MP assets as a final content for your specific projects? How do you even imagine a landscape/character/vehicle/materials or code logic not made for your project to fit perfectly your project?
Like let’s say I buy Simple Towns package but they have only single lane roads and I need at least two lane roads and a limo for my game, I guess I have to refund it now? To me, MP assets are suppose to be place-holders, a basis for a prototype or a foundation from which I can extend content by contracting creator. You can use them to establish your pipeline/workflow or learn how something should be done. Sure there will be odd cases when something is so generic that it will work just good enough for you, but refunding landscape because it doesn’t fit specific idea of your game level is just… I don’t think this is a correct way to approach assets on marketplace, it doesn’t work like this even when you contract people, nothing will be exactly as you want.
Nothing personal , I’m biased towards more custom art and code instead of using assets from MP directly as they are. Maybe I’m wrong and too old for this … but I know that it’s impossible to create or find assets that satisfy all criteria.
It’s not sellers fault that there is no way to preview all possible details of the asset. Providing something like a template for building packaged demo for pure art content could be nice (assuming it becomes a standard practice to use it). But I foresee the same rhetoric repeating with code/plugin assets.
Personally I would take a different route - use MP to publish assets that demonstrate your skill, use them as marketing tool and target custom contracting work. I believe it would be more productive environment facilitating easy outsourcing of workload to experts instead of building something that is suppose to please everyone from wannabe devs to veterans.