When I first started brewing, I spent anywhere from $30-$50 per 5 gallon batch. Looking back I find that insane. If you can buy anything in bulk, do so. You can get hops in 4oz packs, 1# packs, etc. This cuts down on cost a lot. If you brewed all-grain and bought your grain in bulk, you can save a ton of money. Rinse your yeast after taking your beer off primary and you'll save a ton there as well. My last 5gal batch I brewed cost me $8.75.