2007 Nissan Maxima Battery

My mother-in-law had to have her battery replaced recently. When they called from the dealership to tell her it was her battery that needed replaced they also told her they were going to have reset her computer. This repair cost her $250. First, did her computer need to be reset and second is this amount excessive? She is recently widowed and we are afraid they are taking advantage of her. A month ago she had to have her oil changed and that trip cost her about $300. They told her she needed a steering wheel fluid flush and a transmission fluid flush, which she agreed to do.