A $40 Watermelon

I like to keep my blogs in chronological order, but I need to skip ahead to today and share an amazing/shocking bit.  We are traveling in Russia and are blown away at the cost of living. It is not comparable to anything we've ever encountered. I read online that the average loaf of bread of costs $7.50.  We usually buy groceries to avoid eating out with kids when traveling -- it is less expensive and less chaotic.   So we have been in grocery stores in St. Petersburg and again today in Moscow.  We picked up a small watermelon in the grocery store today (not a touristy place) and didn't pay much attention to the price because they are in season, and there was a fairly large display of them.  When we were checking out we saw the roubles on the cash register and we almost choked.  I did some rough rouble to dollar math and realized it was about $40.  Yikes.  We kindly asked the cashier to please put it back on the shelf for us.  As for things we did buy...
1 liter of milk: $2.40
6 eggs: $2
1 small box of muesli/granola/cereal something: $7 (the cheapest we could find)
A large bottle of drinking water: $2
So, for those of you in California and the northeast US, how do these prices compare?