Is there is issur of throwing away money (i.e. sweeping before Shabbos and discarding a few cents/agurot found on the floor)?
Answer:
The prohibition of Bal Tashchis applies to all things that are of value and use, so that in principle it is forbidden to throw away money.
However, if the effort required to retain the money does not justify the value of the money in question, there is no obligation to pick up the money (for instance, if you would pay somebody else a cent to pick up the cent, you wouldn’t have to pick it up).
This is not consiered Bal Tashchis, because the money is saving you the undesired effort of picking it up. However, if there is no significant effort involved, it is correct to pick up the money and not to waste it.
Best wishes.
