I think this should happen through the black market.
It would give scouts additional use as an indirect source of income: Black Market will pay every 60 seconds (or more) for up-to-date information about each gravwell. A list of buttons (scrollable if needed), one for each gravwell, would be available. The only buttons not grayed out are the buttons of the gravwell the player has recent information about. The first player to sell the info gets the cash, then a 'cooldown' of at least 60 seconds would be in place for that gravwell, before the black market gets interested in having information about that gravwell again.
If the player is in dire need of cash, he could sell info about his own gravwells (or maybe not?), but that would potentially benefit other players.
Likewise, players would be able to buy info about a specific gravwell, but it would be like the current intel reports about gravwells covered by fog-of-war: The info would be tagged about how old it is.
I would also like to see ghosts of the last grawell structures/ships seen on gravwells covered by fog of war. Currently, if we zoom in a gravwell where thare are no ships or structures owned by me, I can't see anything, just the plain planet/roid/cloud as if it were virgin, and the intel report at the side with the age. Seeing the last configuration seen by a ship which travelled there would be better.