As usual I live in a limited place when it comes to buying local but this is what I have found.
If I buy my own recipe I will pay about $40 for 5 gallons. That is malt, grains, hops, and yeast. My alcohol level is general somewhere around 7-9%. The Brewers Best kits generally run about $25 at my local store and comes with around 6lbs of malt (syrup or dry), yeast pack, grains, hops, bag for grains, bottle caps, and priming sugar.
A friend of mine that has recently gotten into the hobby has made nothing but kits and has stuck to the kits only. Generally a kit is set up to give you a good flavor for the type of brew you are making with around 4-5% alcohol by volume. Drinking these I can say they are good but then I could buy something off the shelves with about the same taste and kick.
For me I normally will add in around 3 more pounds of malt and usually around a pound of corn sugar just to add a bit more kick. In the end I spend about $25 on a kit, $10 on some extra malt, and $2 on some sugar. So I have about $32 invested plus I get the caps & bottling sugar to add on to the savings. So I save somewhere around about $9 per 5 gallon batch.
Not only that but my batch still has the flavors the kit was going for and people can get that buzz factor on around half the brew. OK so many say taste is more important than kick but if I can get a tasty brew with kick then there you go, best of both.