To stop tanking for PP, perhaps provide a flat 25K bonus for every promotion to a new level for the first time. 10K to everyone who avoids relegation. That would probably be more points than most people currently earn, but obviously less "fun".
Optionally, achievement points could still be tracked, but can only be collected by making an in game purchase of 1% PP per dollar spent. So, if spend $500 get whatever $500 buys PLUS 500% of your achievement points for that week. Tankers would then have to pay to collect
