weird idle on 2002 Mitsubishi Galant

i just bought my 2002 mitsubishi galant for 850.00 the man said the only thing it needs is a wheel bearing. I havnt noticed many problems with it but i dont kno much about cars and i just got it yesterday. when i sit at a stop sign or traffic light it flutters n shakes slightly during idle. is this problem fixable and is it expensive???

for 850, it wont be perfect.
is the check engine light on?? if it is, we need the code number to halp you.
any problem is fixable but the question is if it is worth it.
the wheel bearing, which one, front or rear??

yes the check engine light is on.... im pretty sure its the front wheel bearing someone had sed the fluttering could be the intake valve because it sat for a while.... is this true is this car even worth my time??? did i spend all of my money for nothing??? im 23 years old i have two small children i dont know much about cars except how to drive them. I dont want to put my children in this car if its not safe.. please help
get us the code number so we can help you. you can get the code for free from autozone or pepboys for free.
the front wheel bearing will run around 250 parts and labor.

thanks alot im at work now but i get out at three i will take it right to auto zone and i will have the code for u guys when i get in tomorrow morning again thanks alot cause im lost....
ok i took it to auto zone they told me the only thing showing up is a sparkplug misfire..... what does this mean am i in trouble???