Consider guaranteed vs reviewable premiums
Whichever payment method you choose, you also need to find out whether or not it’s a fixed payment or not – usually called 'guaranteed premiums'. If it is, you know your payments will be the same for the duration of your policy.
If you choose 'reviewable premiums' because it seems cheaper, be aware that after a while the provider could increase the premium.
Apart from switching to a new policy there's nothing you can do about any increases (if you choose to switch, just be mindful that as you get older your health might decline and it may be more expensive to get a new policy at that point).