> "no point giving commission to a travel-agent when you can plan it yourself."
Travel agents often purchase in bulk and can get discounts that you can't get via 'do it yourself' flight tools. I recently travelled to Vancouver and Helsinki from New Zealand (effectively a round-world ticket) that worked out about $NZ 700 cheaper via an agent than online.
Good agents are also adept at 'working the system' - ie, knowing when and where cheap flights are available, upcoming deals, etc. It would pay to check whether your agent can do a better deal before booking online.