The £65 is under category 'Visit'. The £515 is under category 'settlement'.
If you are married and plan to make a short visit to UK, you will pay £65.
If you are married, and intend to live in UK as a permanent resident, you will pay £515.
If you are applying for a visa to allow you to come to UK with the intention of marrying and applying for permanent residency, then you require 'Marriage' visa, which is also under category 'settlement' and you will pay £515.