The cheapest way to buy into Mac is a Mini, but even the "top" $999 one has no SSD, only 8GB of RAM, and a older i5. Compare that with a $500 PC, you can get a legitimately high end developer machine including [basic] monitors and the whole works for that.
Then you need to buy Parallels at $99/year and a bunch of Mac/Apple specific accessories which add up fast. This is particularly important since Bootcamp is garbage, Parallels is the only good way to run Windows or Linux side by side (which in our multi-device world is important).
I could likely even afford to spend $1K on a Mac. I just don't feel like if I did so I'd wind up with a good developer machine that will last me three or four years. Seems like $2400 is about the minimum buy-in.