Pretty early in my software career I had a job at a very awful company [0]. They wanted me to use the software "Weblog Analyzer" to analyze Apache logs and create reports that no one actually read. I was to do this twice a week. It wasn't hard and it only took like fifteen minutes so I didn't really mind doing it.
Initially I had a 30 or 60 day trial for the software, but once that expired the software (understandably) stopped working. I went to the director of technology, asking him to buy me to the software, and he responded back with "whoooa, hold up, that's not within the budget". To be clear, this software was, I believe, less than $100.
I responded back with something like "Ok, well then I'm not going to make these reports anymore". He acted surprised, like I was starting some kind of fucking mutiny, and he asked me why I'm being difficult. I said something to the effect of "I don't make that much money as it is, and I'm not going to spend my own money to make your company more money". [1]
He responded back with "Well [my direct manager] never asked me to buy this software", to which I responded with "Well [manager] is a moron who doesn't know anything".
Like a fucking sitcom, unbeknownst to me my manager was right behind me and heard the entire conversation. The next day I was fired. I don't completely blame them, it was admittedly very mean to say that about my manager even though I did (and still do) believe it.
I later found out that my manager had actually asked for the software years before, the director had said no and forgotten, and my direct manager had just bought the software with their own money.
Point is, at least some employers seem to have no issues making employees pay for their own tools, even for tools that they very specifically want the employees to use.
[0] This was a W2 job, not a contract gig.
[1] I even offered to try and find some alternative free software that might give us something similar, but he immediately poopoo'd that idea because they really liked these very specific charts that they never actually read.