start advertising with stats on few forums and sedo. try that out and then go for broker if u still not sure on price.
Bodis.com is a better place t sell domains and if it's developed you can sell it at flippa too. Digitalpoint and Namepros are other options to sell a domain, but you may not get the right price. And if you are wanting a broker you might be thinking your domain is worth a lot, but make to appraise it first to see if it's worth to pay for a broker. Professional brokers are not cheap to hire and only go for premium domain names most of the times.