Yes, I've been living in Paris and London, 2 of the most expensive cities in the world. By the way, I've also lived in Mali, where it was not as easy as one would think to eat for less than $4 per day.
Soylent's tag line is "What if you never had to worry about food again?" If their goal is to focus on healthy eating, then they need to rethink their messaging. The entire message is about the speed of eating. "Eat quick...eat cheaper".
"...never had to worry about food again..." Where in that statement is there any ambiguity about their desire to take market share away from home-cooked meals?
Don't get me wrong, if they can make a business out of it, that is great. However, it strikes me that it would be far more profitable, on an individual level, to buy cheap food from the produce section of a grocery store, and healthier.