I am terrified I will lose, so want to get another ASAP! I am sure the keys are ridiculously expensive, hoping not over $300 does anyone know how much and can I only get at dealership?
I would not go to the dealer. I had same situation with a 2012 rav 4. I bought the transponder key for 39.95 from eBay. And locksmith programmed for $40. Make sure you get transponder key that corresponds with your year make and model. Good luck.
In general you might just be wasting you money in trying to get a ebay sourced key to work. The keys are designed to only pair with one car. Do more research on PriusChat since some people have claimed that SOME locksmiths (with the right software) have managed to reprogram used keys. It is advisable to get a second key since the dealer will have major problems if you loose the ONLY key. It might cost $1000 to tow you car and get a new key in that case.