I made a small list of item values to check whether an item is valuable or not at the trader. To do this I checked how many stencils one can buy with a specified item. Later on, I found out that spray cans would be better to compare than stencils, because they have a lower value so it would be more exact. But I already had a big part of the list and I didn't want to check every item once again.
I am adding new items to the list once I checked them.

Maybe someone can use it: https://docs.google.com/spreadsheets/d/ ... mL7BM3EEc/

When I wrote ~0 at the value, I was not sure if it was really 0 or just an incredibly low value.

Since you can't edit it directly, you are free to copy this list and release your own version.