Edit: The amount of money produced by the lemonstand is not correctly added to the "Cash earned". It seems that lemonstand produces to quickly for all the money to be properly added.
The cash earned by the lemonstands at level 1000 is not added to "Cash earned" and "All Time Cash earned". We have currently 120 nonnillon money to spend but we have only 71 nonillion cash "Cash earned". So the important question is if the money made by 1000 lemonstands is counted towards the angel invosters, because if this is not the case it is not worth building the lemonstand above 900.