Good question. Based on some of the previous posts, I'd think $20-30/day, perhaps plus lunch. Not necessarily looking for a tour guide, just someone who can speak (and perhaps more importantly, read) the language.

That's not a bad idea. I'd really prefer to have someone lined up before we go, but if we can't make that happen (or we have a no-show in one city or something), Starbucks sounds like a great place to find somebody last-minute.