Cellular service in the US is quite different from what we're used to back home. I did some market research on this, and here's what I found. Phones here aren't usually sold just like that. Major carriers—well, all of them—like T-Mobile, AT&T, Boost, MetroPCS, and others, offer you a 2-year contract (sometimes 1 year) and sell you the phone very cheaply. For example, when our neighbor decided to buy a phone, he went to AT&T (which is considered one of the most expensive carriers) and instead of buying an iPhone 3G for $500, he got it for $100. He signed a 2-year contract and now has to pay a monthly fee of about $90 or less. What's the point? The point is that they care about how long your contract is. If you sign a 10-year contract, they'll give you a ton of iPhones for free. The other side of this coin is that if you decide to move to the desert to live with the Indians and don't need the phone anymore, breaking the contract costs $300. Besides that, if the contract expires and the neighbor wants to switch to another carrier, he'll go to, say, T-Mobile, where the consultants will just tap their heads, like, 'You bought the phone at AT&T, so use their service.' If the phone is bought at an authorized store, it simply cannot be used with another carrier. They are even branded; for example, it says Samsung on top and T-Mobile on the bottom. They basically brand them.
Since we're on the topic of iPhones, they can only be connected to AT&T here; other carriers don't sell them.
If a J-1 visa holder arrives and their MTS doesn't work here (and it doesn't, trust me), they don't go to authorized cellular centers, but to some hole-in-the-wall shop that sells phones and plans for all carriers (or almost all) and buys a Simple Mobile SIM card. Why? Because it's the cheapest way to get connected. The minimum monthly payment is $40 (unlimited calls across America), $50 for unlimited calls and texts, and $60 for unlimited calls, texts, and 150MB of data (which is hard to use up with local speeds, even though they claim up to 7.5 Mbps). When connecting, you also have to pay $25 for the SIM card and $25 for the number, so the cheapest connection option is $90. THIS INCLUDES ALL TAXES! THIS IS IMPORTANT. For comparison, T-Mobile offers a SIM for $40 (as advertised), which gives 500 minutes of talk time per month (calls only; 500 mins + SMS + web costs $80), but the prices are listed without taxes. When connecting, you'll pay about $75, and then $50 every month, all for 500 minutes. And the unlimited plan that costs $60 at Simple Mobile (including taxes) costs $100 at T-Mobile (excluding taxes).
AT&T's system is even more twisted. It's either 25 cents per minute, or they charge $3 a day if you use the phone at all, plus some other nonsense—I didn't really look into it, but it's expensive regardless. Therefore, if you have a Green Card, you can sign these contracts as much as you want and get cool phones for cheap, and you definitely won't be taking them back to Russia.
J-1 HOLDERS! Don't rush to buy expensive phones! Believe me, you'll find better ways to spend that money. It's better to ask around later at those same hole-in-the-wall shops that sell everything and connect to everything; ask about unlocked phones you're interested in, verify, read online if they will work in Russia—don't act impulsively, or you'll end up broke. If you don't have a Siemens A35, you can definitely get a local SIM card. Don't think that top-tier smartphones cost $100 here; the prices are about the same, maybe slightly lower.
