It's snake specific. About $200.
Reading these guys,
https://www.snake-antivenin.com
Shelf life of 5 years.
Cell phone or two-way radio. Barring those, a flare gun and orange/red/whatever color smoke.
I watched a few episodes of that Doc in S. California that specializes in snake bites. By the time they knew if it had venom or was a dry bite, the patient was way past self medicating.Blood test have to be done to know how much to administer.
Trying to give yourself the right amount of antivenin would like like tying to give yourself enough chemo to fight a cancer.
IF you could ever get ahold of some, and IF you could store it, you could end up killing yourself trying to save yourself.