Yes, well it depends on where you are at, but it would be reasonably priced for middle-class families to afford at least some land. That is not us currently, but we are hoping to get there one day.
Grocery prices seem to vary wildly dependent on location and sometimes prices will jump a huge amount overnight. The USDA has a chart here http://www.cnpp.usda.gov/USDAFoodCost-Home.htm and you could look at your families numbers to see what the average is, but it will still vary depending on location. For our family, with 6 kids, we would be comfortable with $300 a week, but that would be all conventional foods, not organic or grass-fed or whatever. We can do it for less and often do, but that means a lot of rice and beans sometimes. We also have to eat gf, which means either no breads, pasta, ect... or paying a lot for them. Some specific prices from a trip the other day - $3.49 for 32oz. yogurt, $1.99 for a dozen large eggs, $3.19 for a lb. of butter, $3.29 for a gallon of milk, $5.79 for a lb. of grass-fed ground beef, $4.99 for 10lbs. potatoes. Not sure if the potatoes were organic or conventional, I usually pay $2.99 for conventional but they could have jumped in price.
It does appear that way. I guess if we only had a couple of kids, we could get a higher efficiency car. Not really sure what is available with that, but I am not aware of any larger vehicles that get more than 10 to 15mpg. It would be really nice if they would work on doing that. But there probably isn't too much of a market.