Hi, Im new to cricket and flashing, but if I buy a bad esn samsung upstage and flash it with cricket software, like a phone flashing kit on ebay for $20, can I activate it on jump mobile, which is owned by cricket I think? I would just use it for calling and texting, and I would put music on the memory card. My friend has had two cricket phones on jump, but she says her cousin takes care of her bill. Thanks so much!