Here is what I found out. I went into my local Lexus dealer 2 months ago and asked about getting a replacement key fob for my 2004 RX330. They gave me the regular $145 speech. Then one of the parts guys told me they would get in blanks in about a month. I went back a month later, and they had them. They took my current key, cut a new one on the spot, and put the electronics from my old key to the new on (just undo a screw and it fits right in). This took 10 minutes and cost me $40. The only difference is that the Lexus logo isn't inscribed on the back of the key.
In other words, call the parts dept of your local dealer and ask if they have blanks in stock. If anything it is worth a shot.
Hope this helps.