You might be surprised by the ridiculously small amount of money it takes to lobby legislators in the US. I've seen various reports over the years that have shown amounts well below $50k effectively buying deciding votes on important issues. To me, that would have otherwise seemed like an amount that might be effective at a city or state level, but it's shocking to see that being true at a federal level. One recent example that was heavily reported on was the lobbying over net neutrality. ISPs contributed $1.5 million to 273 members of Congress to support overturning net neutrality - that's less than $5500 each on average.

https://www.opensecrets.org/news/2017/12/money-flows-into-ne...