If you're in Sydney, Australia, head an hour north to visit the Australian Reptile Park. It's a small zoo that additionally specialises in snakes and spiders that can kill you. It is the sole source of the venom that gets used to make Australia's anti-venoms [1].
The Australian Reptile Park may be related to the cost aspect, in that their program provides a ready supply of the raw materials needed for anti-venom.
Incidentally they collect funnel web spiders for venom production and have a collection network, whereby people can harvest funnel web spiders from their backyards and drop them into collection points around Sydney [2].
Cost is a recognised factor in anti-venoms, and there is ongoing research to reduce their cost [3].
[1] https://www.reptilepark.com.au/animals-at-the-australian-rep...
[2] https://www.reptilepark.com.au/animals-at-the-australian-rep...
[3] https://www.newcastle.edu.au/research/stories/research-impac...