I buy DME and hops in bulk.
Let's say I paid $140. for 55# (not including shipping cost because there were lots more supplies ordered)...that's about 2.55/lb. Let's say I use 6 lbs...that's $15.30...and 9 batches from a box...
Hops are about $12.00/lb..or .75 an oz. I use about 1 oz per batch.
That's $16.30. I rewash most of my yeast. I get 4 batches from the 1st batch. (that's 5) and 4 more from each of the 4 that's 16 more and 4 more per/from the 3rd generation. So, to keep it simple let's say I only get 12 uses out of 1 vial costing $7.95 / 12 = $0.66
That's just under $16.00 a batch for about 37 0,5 liter bottles. At any beer store you can find Hefe Weizen (my favorite style and I brew a lot of it) ranging from 1.85 to 2.45...that's $68.45 to $90.65. If I got 4 minikegs that would be what? $18.00 per or $72.00, but all this is just rough guessing.
Since I get 9 batches from a box and 16 oz from a lb of hops all I have to do is make 2 batches and I am already past the break even point. If I upped the malt to 7 lbs I'm still getting 7 plus batches. The rest is just free beer!
Good deal? I think so.