My only reocurring cost is grain. I'll buy base grain in bulk and any specialty grains by the pound. Reusing yeast, growing my own hops, having water I don't have to drive to buy (a huge inconvenience and a waste of money) keeps my overall costs to 12-20 dollars for a 5 gallon batch, depending on what I'm brewing. If I am using a different yeast or hops, prices tend to increase a little more.
Intermittent costs include propane (every 3rd batch per tank), CO2 (about every 12ish kegs), small odds and ends like tubing, whirlflock, camden, starsan, etc. I don't include those in the cost per gallon every time. If I did, it jumps to roughly 30ish dollars per 5 gallon batch.
My equipment, trellis system for hops, kegging odds and ends have long been paid for so it's not at all included in cost per batch.
Still, if a 6er is $9-$14, 5 gallons will run you roughly $72 to $112, depending on what you buy. Since I rarely buy beer at a store anymore, I would say I'm saving money.
Of course, one could argue that NOT brewing and not buying beer also saves money, but that is just silly nonsense.