I'm trying to buy a cheap cellphone off of the internet and I found one that's unlocked and I really like it but it's 900/1800/1900 as compared to Rogers Canada's 850/1900. If I buy it does that mean it won't work? OR will I get less coverage? Or does Rogers distribute both frequencies everywhere? Any Help would be much appreciated!
P.S. If I do buy it do i just put in my current SIM card and it'll work?

P.P.S. The phone isn't 3g and neither is my SIM card