Ive been searching for 3 months now for a greater siren and i cant find anyone who has them in stock right now. If anyone knows where to get one or has one for sale let me know. Thanks!
You could try a wanted ad on caudata.org. That's where I got mine. I believe it is legal for you to collect your own in FL, but don't take my word for it.
If you are willing to drive, there is a local store here selling them for $25 I think. They are nice sized ones too. Otherwise, go to reptile shows and keep an eye out.