They're coming for a whole week in October, so I need a hotel/b&b/telo/palatial estate for them in the Centro (pref), but something I could pay for on my 3rd world budget. Any recommendations would be mucho appreciated!
Usually the best thing to do for a week or more stays is to rent them a furnished apartment. You might already find many of the best ones already reserved, but it's worth a shot. Based on what you'd otherwise spend on hotels, they will have a MUCh nicer place. Try www.bytargentina.com for starters. Good luck and have fun!