I'll add my experience to the mix.
I started my habit when I received a Mr. Beer kit for X-mas a few years back. I tried it, I enjoyed the hobby, but after 4 batches, I found I spent more time waiting for beer than drinking it.
So I jumped into my first full batch of extract. Bought some cheap 5gal food-grade buckets and split a 6 gal batch into 2 3gals (one dry hopped). They turned out OK, but the Mr. Beer batches tasted better.
So I thought, lets try going to AG. I converted a free cooler to a mash tun, got a turkey-fryer and an extra (bigger) pot. Made myself a wort chiller, and picked up a bigger fermenting bucket.
I picked up the grains to try some Centennial Blonde Ale, and mashed away. Best beer I had made yet! The next few brews, i tweaked the recipe around to increase the ABV.
I'm on my 4th batch of All Grain: 3 variations of Centennial Blonde, and my first shot at Oktoberfest, and they have all come out terrific despite all my efforts in screwing up various steps
For those wanting to move to AG, it really isn't that expensive. I made the jump for under $150 (could have done it for around $100 if I didn't splurge for an extra pot and fermenting bucket).
I've calculated my total expenditures at $419 (started kegging recently) , while my savings of not buying commercial beers has reached $200. Had I not started Kegging, I'd have made my money back already, but then again, I didn't get into it to save money