You are correct.
I think the point of the thread, how cheaply can I make a nice tasting beer is very worthwhile.
Saying I want to make beer for 10 bucks....is abitrary and really not possible when you are taking everything into account(except equipment and labor). Despite how many times someone wants to tell me I'm wrong and then not add things like cleaners, star san, corn sugar(or c02) and boiling power into the equation.
You can probably get pretty close if you back yourself into some ridiculous ingredient costs and brew with electric or nat gas, save star san, dont pitch an appropriate ammount of reused viable yeast cells, ect.
I tend to go about it the other direction. I want to make the most high quality beers possible at the lowest cost, but thats just me based on my circumstances.
Its possible. I bet you don't count supplies, or where your money goes with the supplies you get but a lot of us do that's why many of us can make a 10$ batch feasible. I'll break a recipe down for you so you can see it work.
Lets say Centennial (c-type) Blonde, which makes a pretty darn good beer.
6 lbs, 9 oz 2-row @ 35$/55lb bag = $0.63/lb. = 4.13
11.3 oz cara-pils @ 1.79/lb from LHBS = 1.26
7.5 oz vienna @ 1.70/lb = 0.80
7.5 crystal 10 @ 1.70/lb = 0.80
1/2 oz C-type @ 1.10/oz = 0.55
1/2 oz cascade @ 1.10/oz = 0.55 (or free if you have home grown like I did)
Washed yeast, starter made from wort taken from last batch = 9 batches so far with it so... 3.99/9= 0.44. But this is going to keep going and will get cheaper.
Propane= 1.66 per batch. Last tank @ 20$ lasted me over 12 hours. 20/12= 1.66 with a ROLLING boil.
Star san= 7.99/8 oz. I have about 4 oz left after 25 batches, so I assume 50 batches for the bottle but I'm guessing i'll get even more out of it. I use a spay bottle. No infections either. So 7.99/50= 0.16/batch.
Sugar (table) from wegmans = I believe 2.99$/5lbs @ 3.5 oz/batch = 0.13
Caps= 2.99/144= 1$/50
Grand total of 11.35 assuming
1) you don't use a different sanitizer, don't use swing tops to bottle (I have 1 g worth of these), don't have home grown hops, and use propane, and you have only used the yeast for only 9 batches.
10$ is feasible. Starters (if needed) can be made from wort form the previous batch. I collect a little extra if I know I'm not making successive batches and use that. I also get 78-low 80's depending on the batch for efficiency. And I make a darn good variety of tasty beers.
Toasting your own will save another 2$, swing tops another 1$, more batches with the same yeast $0.30, electric another 1$, home grown hops another 1$....
If you did any of the above you can get below 10$ easily.