Not quite positive about snake anti-venom, I did a cursory search but found nothing to compare, but other anti-venoms....
Same drug from the same drug maker sells for $100 per vial in Mexico and $12,500 per vial in the states. That is criminally absurd. Add to the fact that they never tell you beforehand that "Hey, just FYI you are going to need 4 of these vials, maybe more, and they cost half a car each". Hell even if you ask how much they won't give you an answer. That is illegal in every single other industry in the country. Yes I know there are times that you will be incapable of understanding or making a rational decision but the vast majority of medical care does not fit that category.
http://www.azcentral.com/news/articles/2011/11/10/20111110scorpion-drug-cost.html
Also, I personally know a veterinarian that says the normal charge for treating a rattlesnake bite with the same antivenom (different brand, same exact shit), regardless if its a horse or dog, for $1,500. That includes his time and the cost of the antivenom. Bottom line is the shit shouldn't be nearly as expensive as it is but since you have absolutely zero choice but to bend over and take it and they aren't even nice enough to spit on it for you.