Ask the agents why the quote is higher than you expected and if there are any options that can lower the premium. Higher deductibles and being a non-smoker can lower the deductible.
There are unfortunately some things that can drive the price up on a particular home or area you can do nothing about. Crime rates, proximity to the fire department, type and rating of the fire department, frequency of storm damage in the area, etc.
In addition the insurance industry keeps a history of the home (it's called the CLUE database/CLUE report). This information will be used to calculate the risk of insuring this particular home. Claims in the homes past will cause the insurance to go up even for other owners in the future. The home you are buying may have a bad history insurance wise.
Ask your agent why and keep shopping around. Check into things that could lower the payments such as a higher deductible or paying the premium every 6 months instead of monthly. Ask others in the neighborhood what the general premium is in the neighborhood and who they got there insurance from. There are a lot of sites that will give you multiple quotes online as well.