Tom received a gold Rolex watch from his dad as a gift. At the time of the gift, the watch had a FMV of $45,000. Tom's dad received the watch as gift from his dad (Tom's grandfather). When Tom's grandfather gave the watch to Tom's dad, the watch had a FMV of $50,000. Tom's grandfather received the watch from his dad (Tom's great grandfather). When Tom's grandfather received the watch, it had a FMV or $15,000. Tom's great grandfather received the watch as an anniversary gift from his wife. She had purchased the watch for $1,000. 

What is Tom's basis in the watch?