The cost for life insurance for a 25 year old can range from under $10/month to thousands of dollars per month. Whether the 25 year old uses tobacco, has health problems, is getting term or permanent insurance, or is using the life insurance for cash value or life protection .... all of these factors make a big difference in how much the policy will cost.
Prices will vary between companies, and the type of policy you apply for will also determine the price you ultimately pay.
In addition, your tobacco usage as well as your overall health profile will affect your costs.