The first step is figuring out the baseline. Expensive compared to what? In 1978, the1st Edition AD&D Player's Handbook cost me (more likely my mom) $15. This was a black and white book of 127 pages. It was a fantastically creative book that we practically memorized over the coming years. Mine traveled with me on my back through junior high school and most of high school. Back then you could carry every D&D book in a large backpack, and if there was a game after school, sometimes we did that. I sometimes wonder why I didn' t have a girlfriend until college.
The 3.5 Player's Handbook printed in 2005 is full color, 315 pages -- way over twice the size as the original and prettier -- and retails for $29.95. It's certainly a creative masterpiece as well (I think), although we're still unsure of most rules since the 3.0 upgrade. We have a hundred other books to read (121 to be exact), so memorization is out of the question, as is carrying the entire collection in a backpack. I see no love for this book, only acceptance of its utility.
Back to the numbers, we can see that the 3.5 book is possibly twice the production value of the original AD&D book. With a $15 (1978) versus $30 (2005) price difference, does that mean all things are equal? Not even close. How much would that original AD&D book cost if adjusted for inflation? Looking at an inflation calculator we get $48.19. That's right, the black & white original was way more expensive.
Gaming books have actually gone down in price, adjusted for inflation, with massive increases in value. I think the pain and dismay comes from the dearth of new material. It might seem like an embarrassment of riches, but a lot of players are exhausted from those regular releases. They either bite the bullet and buy each book, or they put in place various house rule moratoriums on new books: You can only use core books, or books the DM owns, or Complete books, or the books listed on my website.
I'm clearly a D&D gamer because I anticipate and highly enjoy getting that new book, but even I hesitate to take every one home, and I get them at cost! If you're not financially able to keep up with the hobby, it can be very frustrating and it can seem like an exhausting obligation rather than the wonder and excitement it once was.

