Amended 1099B - how different does it need to be to require an updated filing?

I received an updated 1099B which changed my Federal and State taxes.  Federal increased by $50 and State dropped by $10.  I have already received my Federal refund and paid the state taxes.  I would have to give back the $50 to the feds.  Should I wait for them to ask for the money or file an amended return?