Should I Refinance My Mortgage (interest rate, rate, closing, sell)

[herewego12345]

Hi,

I currently have 4.5 interest rate on my mortgage however rates have fallen down to lower 3.00. I am getting offer to refinance my mortgage with interest rate of 3.500 and closing cost around 3000. Some mortgage agents suggest i should refinance and some don't. What do you think? If i had a rate of 5.5 then it would definitely make sense to refinance but since its only 4.5 then does it still make sense to refinance? I am also planning to sell my coop apartment in 5 years.

Thanks,
Kay