There is certainly the Apple tax being applied. However, I can say from experience that Apple when they construct a laptop, uses the best materials. It was not surprising that the white macbook was discontinued as I found it to be not worth the price with its plastic construction, lower quality keyboard, lower quality hard drive, etc..
All of their Macbook Pro lines are of equal quality.
While it is beyond certain, that for the same price you can get more "muscle" from a regular PC laptop, the quality is in fact not on par with the higher priced apple product.
I've bought and deployed thousands of laptops for various places I've worked for, ranging from low end netbooks to high end workstation replacement laptops. It wasn't until one of the VP's in my company demanded a Macbook Pro I ever even gave it a second look. So when he did, we ordered up a 17" and I had to load it up with software so he could use it. Once I got past the fact it was an Apple and was something I was used to hating, I discovered that this unit was made very well. The screen was noticed first, hinge quality second, and obviously the all metal construction. All in all, I can say that to get a laptop of the same quality, you are going to spend *about* the same amount of money from PC manufacturers. So for a change, I replaced my 5 year old laptop with a new mid 2010 Macbook Pro 17 just like the one the VP demanded, and have been using it ever since.
Apple usually has the most annoying users, and they are delusional because they typically swear the products are perfect.. but I find that when looked at objectively, the line apple puts out it of a quality that justifies the price.
Does it justify for the enthusiast? probably not. Can you buy an equal quality PC? Absolutely, For about the same price, is my only point.