Pet Insurance monthly costs range from $10.00 to $50.00 and even sometimes as high as $100.00 per month depending on the policy you get and who you go with for pet insurance.
For Lifetime Pet Insurance it can cost from $50.00 per month to $100.00 per month as there's really no way to tell unless we know what Pet Insurance Company you're going with and how much coverage you're wanting to buy for your pet.
But expect to pay at least $50.00 per month for lifetime Pet Insurance although you may get lucky and find some lifetime pet insurance a bit cheaper.