I get what you are asking but I'll point out some things.
1. You aren't buying rey with the bundles, you still have to wait for the ship event to come around 7 times to unlock that requirement. (Or wait for the event and drop 6k crystals on refreshes)
2. Rey doesn't need Ben to be "gac ready". Yes Ben helps and makes it more annoying to beat rey but there is no requirement to have Ben in order to use Rey.
3. Buying the bundles doesn't get you to 4m gp (requirement for proving grounds)
4. You can buy the conquest + pass each conquest to half the time needed.
5. You can spend crystals to refresh proving grounds (not sure if there is a limit to how many times you can do this).
6. They are selling 2/5ths of the counter to rey+Ben already (starkiller and Mara jade)
