There is even a site that tells you how much money you'd need to run 51% attacks on different cryptocurrencies. (It looks like the site used Nicehash payouts as a data point but Nicehash is down/being updated so those values are no longer there, but I found an article with a screenshot from May last year.)

https://thenextweb.com/hardfork/2018/05/30/heres-how-much-it...