I've read about how to take a new transponder key and make a new master. However, when I called the local locksmith he threw me a curve-ball by saying that the key he sold could also be a clone of my master. Is there an advantage to doing this? Any disadvantage? Also, the Lexus dealer stated that the only way I could have another master is if I bought the key/3 button fob combo for $200. Is he just trying to get my $$$ or is there some truth to it?

Thanks!
Sean
2002 RX300