just had the same issue, after losing the greykey and destroying my black key (broke the plactic bit then welded a washer to the metal part to so i could turn it in the barrel) i was quoted $990 to come and cut 2 keys and code them in. rang toyota, they wanted more and to change the key barrel and door locks blah blah$$$$.
i found a lock smith in perth. took in my handful of plastic bits and weded up key, they cut me a new key and put a new plastic bit on with my old chip. they also cut me a another key.
cut and replace plastic button bit $80
complete replacement of grey key $150.
A1 locksmiths in morley. really good service.