Considering our industry gets a lot of our software and tools for free, the price of a mac or a good PC really isn't much, especially if you work professionally and make an income off it.
I've bought two Mac laptops in 9 years. It's highly justifiable, considering I didn't have to get a degree, and made a career from basically a £1000 investment and lots of time.
Also, the software you get for Mac is infinitely better than PC. Sketch and Affinity have basically replaced Adobe CC at a fraction of the cost, which is a big saving in itself. For example, Affinity Photo is a one off £29.99, and it gives Photoshop a serious run for its money. I've been using the beta for the last month and haven't needed PS since.