The first thing people need to know is there is little correlation between the purchase price of your home and the cost of your insurance. Insurance cost is based on the cost to rebuild the structure, not the purchase price. Example, a 1,500 sq foot home in Corona Del Mar may cost more than $1,000,000 to purchase, but only $650 to insure, whereas a 3,800 sq foot home in Corona my cost less than $600,000 to purchase, but more than $1,200 to insure.
There are many factors that determine home owner insurance cost, including size of the home, age of the home, past claims history, retired and age 55+, central/local alarmed, fire sprinklers, auto/home insurance discount.
Replacement cost of the home which is determined by the type of building materials used to build the house, territory or zip code, your insurance history such as insurance score and claims history if any, and a few other factors depending on the company. Its always best to get a couple quotes and compare not just rates but also coverage. Some policies are broad form and some are special which are very different contracts. You really need to get some quotes from insurance agents and compare them. Its a bit of work but hopefully the company you get insured with is the one you keep for a while.