Other books have price boosts too such as Betcoin. I don't count those for any of the books since the amounts of plays and wagers are limited.
I think it should still be counted regardless of how many matches you can apply the boosts for. But yes, you are right regarding the limitations. Sportsbet considers its price boosts as promotions/bonuses. You can only use one bet boost per sport in a 24-hour period. Maybe this changes depending on the Clubhouse level you are at. LFC_Bitcoin can correct me if I am wrong.
I think that complicates things too much when doing comparisons. Nitrobetting has a sports bonuses and nice loss backs in NFL up to 15%. Betcoin has 2 lines and boosts. It seems best to throw all that out when comparing lines.