Travel Agents
You should do your own research before purchasing travel insurance from a travel agent.
Travel Agents make large commissions from selling travel insurance to unsuspecting travellers. They are also able to offer large discounts because their standard prices are so high, don't be fooled by them offering 25% or more of the price. This is still likely to cost more than organising and comparing your own insurance.
Often a travel agent will use high pressure tactics, including today only or time of booking discounts to get you to sign up immediately rather than research travel insurance yourself. This is a clear sign that you could do better!
Compare Travel Insurance to see how much it should cost you.