I recognize you name from previous posts and remember that you are located in Flores? If you can't find a futon near where you are, there are a number of furniture shops on Av Santa Fe that sell cheap futons starting at about $500 pesos (including the pine frame). The best are oak and an innerspring futon is optional. I have the latter and paid $1200 pesos about 18 months ago. They are available at one store with multiple locations...one is at the corner of Puerreydon and Santa Fe, but they don't sell the futons there, just linens. I am in California now so I can't be more precise about the location with the futons or the store name (starts with an "A"). The location where I bough the futon was also on Santa Fe and not far from the smaller shop. They arranged the delivery. The futon required assembly, but it took me less than an hour to put it together.If you need to make your own delivery arrangements, I highly recommend Honda Verde Flet: www.hondaverdeflet.com.ar 4961-2244 or 4961-3201You can meet them at the store and ride to your apartment with them or they will pick up and deliver. They may charge for an extra person to help load and unload, and more for each flight of stairs, but the charges have always been reasonable. Just ask in advance.
PS: Prices should be lower in Flores then Recoleta or Palermo...unless they gouge the foreigner. If you shop a bit, you'll find what you need as well as locate sources for lots of other items.
