Keep in mind that while on the surface it may seem that Macs are "more expensive," look at what's under the hood. Each Mac boasts, at a minimum, an i5 intel chipset with duo/quad core depending upon what model you get (currently they're using Ivy Bridge with Haswell coming right around the corner). Throw in the metal unibody structure, built-in high-res camera, the multifunctional Thunderbolt port and glass monitor and it's easy to see why the cost adds up. If you go apples to apples (no pun intended, I swear!) with a PC that has identical specs, you'll find the cost differential between the two is not as great as it may seem.
Mac systems also make use of CoreAudio, meaning that a single unit is responsible for everything audio related right down to MIDI (i.e. CoreMIDI). Developers don't have to worry about catering to an abundance of differing components and sound modules often found with PC's that contain a variety of generic sound cards with differing components from one model to the next, which in turn enables increased stability for software/hardware.
Don't get me wrong, PC's are great and Macs are not without their own problems. I own both systems and personally use Mac's more...however, that's just me and my experience of having been a total tech nerd for 15 plus years. If Linux became a player as large as Windows, I would probably become PC heavy again...but I digress.
It boils down to what you are aiming to do with your system, your budget and how long you intend on using the computer. Don't let anyone's opinion sway you, do the grunt work of research, crunch the numbers, and drop the cash. The most important thing is that you get a computer with an adequate chipset and multiple cores (i.e. greater than duocore).
Cheers.