Life is how you define it, no? I am not sure what average means because there are so much disparity here is boring ol dayton ohio.
Average Gross monthly salary: I would guess somewhere around US$4-5K a month per household. My wife and I are triple that but we live just like the average. Taxes are very high in this burb, there are even city income taxes here.
2 bedroom apartment rent: $800 for the nicest and newest in safe neighborhoods, $300 a month if you don't mind getting shot
Average house price: Inside of dayton you can get a house for a ham sandwich. Outside in the country/burbs: About $200K for a new 4 bedroom/basement on ~1/2 acre. Still kicking myself for not buying that small house on 6 acres for $130K. It had about 30 full grown walnut trees (worth about $1K each) and a horse barn, holy shit.
Big Mac Menu: $6
Volkswagen Golf: $20K I guess
1 Gallon of gas: $3.50
1.5 Liter bottle of Coke: hardly ever buy pop, but those big ass bottles can be bought for a buck on sale
Healthcare a year: I don't understand, with the cost of insurance? Without we still spend quite a bit but I think most people spend far less, maybe $3K a year.
Doctor visit: All over the the place, depends on what's wrong. You have to pay a lot by law if you are uninsured. We have a high yearly deductable, first $5K on us.
Plummer visit: Just spent $80 labor on kitchen faucet installation, took them 40 minutes.
School a year: "Free" and pretty good here, 5 miles away it is crap.
University: $9000 per year (books, but not housing). Just put my son through 4 years at Ohio State. My ex and I gave him a complete ride including a used car. About $100K when you tally the whole. I had to drink cheap beer for a while.
To really answer this question- I bet I could live just dandy by myself on $30K net per year here, even live in a house. With my wife we need minimum about $40K net before real hard choices would be made.