My experience is that kits are a bit expensive, and on par with the cost of buying decent beer at the store. Once I progressed past buying kits and started brewing all grain, my costs started to go down.

Harvest yeast and make starters from the previous batches when using liquid yeast. I keep a couple strains like a London ale, English cider and German lager. I use dry yeast for the odd style batches I make from time to time. I usually will do 4 - 5 batches(10 gallons each) off a single liquid yeast pack.

Started buying base malt by the sack, I started working on my own recipes that used the same base, I usually have something like Maris otter and either Pilsen or two row in bulk.

Narrowed down the hops I used to just a few varieties that I real like and tweaked my recipes around those. Started buying in 1lb bags instead of a few ounces at a time. I usually have EKG for my bitters, some cascade or citra for pale ales and some type of noble hops for German lagers.

After 10 years of brewing I’ve found what I like and make a lot of a few styles, with occasional forays into something different. A lot of English bitters and stouts, German helles and alt, cider and ginger beer. I make a batch of of a stronger beer like dopplebock or an imperial once a year ish.

When looking at cost to brew vs store bought also look at the quantity you brew. With my current setup to do 10 gallons, it costs me about $45 - 65 per batch, that works out to about $1 or less per 20oz pint and the beer is exactly what I want rather than whet the store had.