About to buy an Iphone - Some questions

I've never been really big into phones or anything of the sort but I'm interesting in buying an iphone. I've been looking for an unlocked iPhone 3G and I got a few questions before I buy anything.

If it matters, I live in canada.

1. How much should an unlocked 3g cost? I would assume around the $300 price range.

2. At the moment, I do not have a sim card but if I do get an iphone, can I simply bring it to Rogers/Fido and they will simply give me one (upon choosing a plan of course)?

3. If I want a data plan/internet access, would I have to pay anything? I recall someone telling me that if I buy an unlocked iphone, I wouldn't have to pay for a data plan. I would still have internet access free of charge through wifi right?

1. If you're in Canada you should be able to find unlocked 3G iphones from $300 to $400 depending on the condition of the phone. I sell factory unlocked 3G 16GB iPhones in USA for $500.

2. The cell phone provider will provide you the sim card, but it probably won't be free of charge. Call and find out from the provider first. It's up to them

3. Data plan charges are dependent on the provider as well. You don't need to have one on the iPhone because it can access the internet through WiFi, but some carriers make you have a data plan with any smartphone.