Is refinancing my home right for me right now?

I currently have a 30 year fixed at 70000 and a HELOC with a balance of 10000. Original loan is 4 and a half years old at 6.25%. HELOC is interest only at 7.25%

Minimum payments are 560 on original and 60 on HELOC(although I try to pay 100 there)

I just ran my credit report and TransUnion says my score is 752.

Broker is advising me that closing cost will be 2400 & they can roll it into new loan for a principle balance of 83000. With an interest rate at 5%, he say total monthly payment will be 580.

According to my math, it would take me about 13 mos., to start 'saving' money in the long run and of course, my monthly output would be immediately reduced.

However, I plan on selling in 2 years (plans, like life, subject to change)

Any advice? Would it be wise to refi., even if I plan on selling in just a couple of years?

Also, are these 'closing costs' negotiable in any way?

Thanks in Advance...Much Peace...