The closest I've come across online is the treasure generator at donjon, which can combine several treasure parcels of the same level into a single hoard. In your example, that would mean the generator rolls on the '1st level' sub-table until it has a total treasure of around 2000gp. Just to clarify: Do you mean a generator that basically continues rolling on the treasure table at the user's requested LEVEL until it gets to an amount roughly equal to the user's requested GP_VALUE?
