Key cutting and lock craziness

I got a fob and one key with my 2003 Prius. I don't think I have that smart key system since I don't have one of those power start buttons. I love the car so far but the ignition key won't open the back hatch. Is that normal? I guess the dealer should have given me a hatch key. Second, when I got home Wednesday I couldn't get out of the car. I think the cable to the interior pull detached. I can open the drivers door from the outside but not the inside. But based on the multiple fob modes I have to wonder if something else is going on. I went in to Home Depot to cut an extra key but he said my key has a transmitter chip inside of it so I could open the door but I couldn't start the car. What kind of crazy belt and suspenders protection is that? What possible virtue could there be other than making me go to the Toyota dealer to buy a super expensive and fat headed key that I won't want to keep in my wallet for backup?

Aside from this "feature" I pretty much love everything else about the car.

 

Well I have to thank you for the great detailed information especially to the degree its money saving. I thought it would be more to re-key the trunk. I'd really like to get in with the key. I don't understand the point at all of having a key with a transponder in it.
I find it frustrating. I get no benefit out of it, but Toyota gets to sell me extras at fifty bucks a pop and it costs them two bucks tops.

 

I just bought a key for 9.95 by skipping the Ebay store and going right to the seller's home page. His shipping is ridiculous for mailing a key, but there was no sales tax. The total was 16.90. And I guess since there have been ignition transponders put in cars car thefts have gone way down...at least according to the website. I still resent paying sixteen dollars for a key for my not so new Prius. But its not too bitter a pill to swallow. Thanks for saving me thirty to fifty bucks.