There are several knife stores in Once that sell wholesale- I think they are on Peron. There are also several artisan stores that sell stuff from the country much cheaper- again, wholesale, basically. There are a couple on Larrera, I think, although basically, you have to walk around and look.
Also, the wholesale restaurant district has lots of choices, cheap, over on the corner of Jujuy y Juan de Garay, mas o menos.
You want to save money, you have to work at it a bit, and take the collectivo over there.
You want convenience, you pay more for it.
And, obviously, you pay more for imported stuff, especially in fancy barrios like Recoleta or Palermo.