Keep in mind that all commissions are negotiable between you and your agent--there are no set standards-- when choosing any flat fee realty company, do shop around and choose the one with the most to offer.... more
There are a couple of North Shore brokers who are regulars on Trulia Voices who will certainly be answering soon. Your best bet is to hook-up with one of them and have them come take a look. Seek out a neighborhood expert to get the best advice on potential current market value for your home.
Keep in mind, if you're buying again in this market, you will probably "make up the difference" of anything you might lose on your sale.