Another suggestion for the use of bs. Special skills could be sold at high price. These 'special' active and passive skills will run on bs and will not have a set number of matches due for expiry.
Eg. Special active skill uppercut costs 5bs to run per match. So long as you have 5bs in your account, you can continue to use this uppercut skill in game.
The moment you have less than 5bs in the account, the skill will be unusable, thus you must obtain bs till you have at least 5bs again before the skill will work. This will bring great convenience to the players whereby they do not have to worry about their skill packs running out and provides another option of practical use for their bs. Figures can vary, but you'll most likely get the point.