Making beer is usually cheaper per bottle than buying good craft beer. There are some howevers, that in the long run, make it more expensive than purchasing good craft beer.
However #1:
You'll end up brewing more beer than you'd have purchased. For some of us, this leads to drinking more beer. As for me, I brew a lot more beer than I would ever buy, but my consumption hasn't increased at all (at least I don't think it has). I just give a lot of it away now!
However #2:
On occasion you'll make a batch of beer that is quite expensive! I'm making a fruit cake flavored Oud Bruin that is quite expensive. The beer ingredients (grains, hops, yeast) for five gallons were $67. This puts it on par with the average cost for a six pack of a good craft beer. However, the fruits that went in (1.5# each of Sour Cherries, Raisins, Cranberries, Figs, Dates and Black Currants) ran me $76. I'm now at double the cost of an average good craft beer. I created a split batch of two different basic wort sours for this batch, which ran me about $42. My total cost for 10 gallons is now approaching $185. I expect 108 bottles of beer out of this batch, so my cost per bottle is about $1.71, which is $10.27 per six pack. More expensive than the average craft beer.
However #3:
Equipment costs. You'll find yourself always wanting more equipment. With me it's more fermenters. I now have 11 fermenters, with a capacity between them to keep 55 gallons fermenting at anyone time. Keezer...I'm building one out of a chest freezer. I have about $300 in it so far, and expect to ultimately spend another $400 on it by the time I'm finished with it. I'll then have 5 beers on tap. This isn't counting, new hoses, autosiphons, hydrometers, refractometers, larger boil pots as you grow, etc., etc., etc.
However #4:
Books. Yes, books. My library now has about 15 books in it, at an average cost of $20 (this is a guess), I have $300 invested in my library.
As you can see, you won't save money brewing your own beer. Very few hobbies actually pay for themselves. Brewing only pays for itself if you go pro, or if you keep it to only brewing basic beers at the quantities that you can personally drink. If you make more beer than you would have consumed, if you didn't make beer, it will cost more in the long run.