It looks like the boost Multiplier is 1.5. If you had 1,000 boosts before, you should have 1,500 now. Mine seems to have calculated correctly if this is the case (rounded up to the nearest whole number).
If this is the case, new boost sales should be priced at 30 hard cash for one boost (old was 20 hard cash per boost). If this changes and the new boosts cost less now, I can imagine there will be a lot of chargebacks for Ludia.