Help My Sister Get a Laptop For College

So my sister, who is AMAZING, has just started college yesterday. She is in need of a laptop for school and needing some help. She is a single mom to 3 (well 1 on the way) and is trying to better her life as well as her daughters life. She is strong and determined to get this. My sister struggles with an incurrable disease called Crohns Disease so this is a HUGE step for her. Please help anyway possible. The computer she picked out is the cheapest Walmart has at $299 or so, but I would love to raise more so she can get a warranty and carrying case for it.   Thank you all so much and God Bless Stephanie (Ashley's Sister)