This expert is helping you out because there weren't many active Sprint Nextel experts.
IF it's a regular Sprint phone it will not be able to buy cards for it. But if it's a virgin mobile or a boost than yeah you could buy cards for those otherwise you might want to go and take that sprint phone and you could turn it into a cricket phone by having them flash the software
I have been in the wireless industry for over six years and have split the time between Verizon Wireless and Sprint Nextel. I currently manage a Sprint Nextel "A" store. The "A" denotes the amount of traffic the store receives. A stores are the second to most busiest after "A 100" stores (there are only 100 of those in the country). My store is a full service and repair store in Las Vegas NV. I am very knowledgeable in every aspect of Sprint Nextel daily operations from current promotions that are going on to billing questions. In addition, I know just about everything that you need to know about the devices. If you are looking for answers on how to jailbreak your phone, I am sorry but I cannot legally answer those as it will void out your warranty. However, if you are looking for answers on how to best handle any situation with Sprint then I am your guy. If you are looking to upgrade early or get an extra credit on the bill I can help you depending on your situation.