Welcome on board eqeman 
I am publishing some figures about the cost of living in Amman so that you can an approximate idea.
Restaurants
Meal, Inexpensive Restaurant 7.67 $
Meal for 2, Mid-range Restaurant 27.91 $
Combo Meal at McDonalds or Similar 7.21 $
Domestic Beer (0.5 liter draught) 4.02 $
Imported Beer (0.33 liter bottle) 6.03 $
Coke/Pepsi (0.33 liter bottle) 0.57 $
Water (0.33 liter bottle) 1.01 $
Markets
Milk (regular), 1 liter 1.73 $
Loaf of Fresh Bread 1.92 $
Eggs (12) 1.42 $
Fresh Cheese (1kg) 15.65 $
Chicken Breasts (Boneless, Skinless), (1kg) 2.64 $
Water (1.5 liter bottle) 0.76 $
Bottle of Wine (Mid-Range) 29.11 $
Domestic Beer (0.5 liter bottle) 1.98 $
Imported Beer (0.33 liter bottle) 5.78 $
Pack of Cigarettes (Marlboro) 2.88 $
Transportation
One-way Ticket (local transport) 0.59 $
Monthly Pass 18.84 $
Taxi (5km within center) 2.40 $
Gasoline (1 liter) 0.79 $
Utilities (Monthly)
Basic (Electricity, Gas, Water, Garbage) 70.10 $
1 min. of Prepaid Mobile Tariff (no discounts or plans) 0.19 $
Internet (2 Mbps ADSL flat) 61.13 $
Sports And Leisure
Fitness Club, Monthly Fee for 1 Adult 65.98 $
Tennis Court Rent (1 Hour on Weekend) 6.60 $
Cinema, International Release, 1 Seat 7.92 $
Hope this might help you meanwhile to calculate your cost of livings based on your income.
Regards
Source: Cost of Living, Numbeo
Figure updated on December 2010