Car insurance is similiar to what I was paying in the states. The only difference is that I paid quarterly in the states and you pay yearly here. When I bought my car brand new, it was close to 5000dhms the first year but has gone down each year. I think this year I paid around 3500 dhms. You won't find the "Wal-mart" deals on TV here, but the TV's can be less than if you went into Best Buy. I use a "pay as you go" cell phone. The phone itself was a little pricey. Find something on ebay that you want before you come over (make sure it takes a sim card), then bring it over, buy a small converter to charge it and you'll be fine. That's what I did for my wife. Only charge then was sim card. I spend less than 100 dhms a month on "charging the time up" on the phone.
In my opinion, all the banks over here are rip-offs. I use HSBC to transfer all my cash back home to my bank there. Then I pay my bills out of my bank at home. It's not that expensive to transfer home each month.
As far as calling home, it's cheap if you use a certain service and buy a "work-around" to use it. I'd suggest you have your laptop setup with it before you get here.