What is the least expensive way to take care of a theft by check class B misdemeanor?

Depends on where the case is pending. In Harris County, if you pay the restitution and fees, they will generally dismiss the case (which is best because it is a theft - a crime of moral turpitude.) However, this is after making a bond & it is on the court's docket. (That said, once I had a client who lived out of state who sent me the payments, etc., & I was able to get them to dismiss the case and recall the warrant without the client making bond or coming to court.) Different counties would handle it different ways. The cheapest way would probably be to call the prosecutor's office & see if you can make arrangements for repayment & dismissal directly. If they won't deal with you, then I suggest you hire a lawyer local to the area and see if they can get the payment / dismissal accomplished for you. You will save travel and bond so you can afford to pay the lawyer.