$100 USD each phone for 7 days plus a small fee for a data package which is inexpensive. A $5 plan has 1000 bytes which is good for 76 position pings @ 13 bytes each. At 12 pings per hour (every 5 min) it is good for 6 riding hours. 1000 bytes is also good for 76 preset messages or 12 custom messages, so it would cover a full 3 day ride for messages. A data package of 4000 bytes or $20 for each phone would be more than enough and falls into the 2000-4000 bytes that most use. The 7 day rental is 7 days plus shipping.