I shifted from PC to Mac and would do it again, because I really like the option to run a computer like a toaster; push a button and it does X. With the PCs, which I used for years, it always seemed like something new was coming up -- needed more security, more security would cause program problems, then you'd have to update the programs...I got tired of it. I suppose (actually, I'm sure) that you can make Macs as complicated as any PC, but if you don't want to do that, if you want to keep the computer aspect of your life simple, then the Mac is the way to go.
However.
You're talking big bucks. You if need Photoshop, you'll need a new one, and a new one runs (at retail) close to $700 bucks, though there are some deals. You may need a Lightroom or an Aperture, you may need a new word processor, etc. And be aware that there's a lot more fairly ideosyncratic software for the PC than for the Mac. With a PC, most of the time, you can think of something you'd like to do, and then go find a program that does it. That doesn't work so well with a Mac.
Also, you may eventually want to add a laptop, and of course, use the same software, so that means a Mac, and Mac laptops are notably more expensive (and there are far fewer configurations) than in the PC world.
Overall, given equal function, I would say that you should be prepared to pay up to twice as much for a Mac than you would for a PC, if you shop hard for the PC. Go look at an Apple store, then go look at the Dell store. Sure, the Dells are ugly, but the function is there.
JC