Personally, I can barely eat half a bife in most parrilla's, so the idea of needing more is kinda hard for me to understand.
Plus, the cheaper the parrilla, the gristlier and fattier the bife- but I guess some people believe in quantity over quality.
Its simple, funky, and local. No hint of the fancy tourists that frequent La Cabrera. But plates of fritas about as big as cafeteria trays, bife for $25 pesos or less.
Most of the really cheap places are NOT in Palermo- why would they be? The rents are higher, and the average clientele in Palermo Soho is far more concerned with being slim and seen than all you can eat.
A bit farther away, in Almagro, but not THAT far, maybe ten blocks from Palermo, is ALE ALE, with all you can eat salad bar, and huge portions of fixed price meal specials with multiple courses- its the kind of place where cheap chowhounds go to shovel it down, but its pretty darn good, if you ask me- Estado de Isreal just a few blocks south of Cordoba. Parrilla, of course, but another 50 pages or so of menu items too... http://www.guiaoleo.com.ar/detail.php?ID=65
There are a few different Chinese parrilla libres withing 1 or 2 blocks from Av. Santa Fe on the streets ~Borges, Thames, Uriarte... and maybe one after.
The beef & chicken are tough as boots, but they've got those items.
A cheaper way to add 20lbs of muscle in 3 months (not that I would ever wish that on anyone who wasn't beefing up for a film role) is to either:
1) Buy eggs by the 30 pack crate. 1 egg = 6 grams of protein... So for about AR$20-AR$30, depending on the verduleria or carniceria where you buy them, you can get 180 grams of protein.
"6 grams of protein" per AR$1 (or more)
2) Where Av. Maria Campos splits off from Av. Santa Fe, there is a "Fitness Store".
There you can buy either WHEY protein (from milk) or EGG protein (you should be able to figure that one out) by the Kilo for about AR$200 (or a bit more), you get ~733 grams of protein.
"3.66 grams of protein" per AR$1
Considering that those Parrilla Libres are about AR$50 (or more these days), you'd have to eat about 183 Grams of Protein (OR MORE) in one sitting just to get your money's worth. Personally, I think that that would be a foolish route to take. In the '80s (pre-P.C.)... I'd say "You're f*cking retarded."... but you can't say that anymore.
So start eating eggs. LOTS of them. Multiple times a day. AND take your vitamins. The good thing about the protein powders is that ( A ) They come chock full of vitamins, ( B ) The Amino Acids in them help you build muscle faster, ( C ) You don't end up eating a week's worth of fat in one serving.
Good luck. Your joints will hate you. But that's beside the point.