Instead of the exponential pricing as it was before, or the flat pricing as it is now, what if the pricing was set as a linear progressive pricing such as 10 per tier. Tier 1 would cost 10, tier 12 would be 120 (780 accumulated), etc. To purchase all 20 tiers in one stat would be an accumulated cost of 2100 (100 more than what it currently is). Lower tiers would be more affordable but unlike the exponential system, players wouldn’t be able to purchase all the way to just a few levels from the top for a low rate. Up to level 10 each tier would be cheaper than the current system and higher than 10 would be more expensive. Accumulated total it would be cheaper until you purchased Tier 19.
Wanted to add that with this type boost pricing it is also more expensive to put all the boosts on just one or two stats. Using a level 24 for examples;
Take 2 stats to T10 and one to T4 costs 1200 accumulated. Average 50 boosts per tier.
Take 2 stats to T11 and one to T2 costs 1350 accumulated. Average 56.25 boosts per tier.
Take 2 stats only to T12 costs 1560 accumulated. Average 65 boosts per tier.
Take 1 stat to T20 and one to T4 costs 2200 accumulated. Average 91.67 boost per tier.
Take all 3 stats to T8 costs 1080 accumulated. Average 45 boost per tier.
In the current system every one of them would cost 2400 accumulated. So this would be cheaper than the current system (except of course T19 accumulated cost would be the same as now and a T20 accumulated cost would be more).
If a new player wanted to boost two stats up to T5 it would cost 300 accumulated with this system instead of 1000. Three stats to T5 would be 450 accumulated instead of 1500.
The higher the tiers a player purchases into the more they will spend on average for all their boosts on that dinosaur.
Spreading out the boosts across more dinosaurs cost less per boost overall.