- What is the benefit of Platinum over 18k white gold?

- How many carats should the diamond be, at a minimum. Would a 0.5 carat diamond look silly small if surrounded with a band of tiny diamonds (halo ring)?

- Is there any specific jewelers that offer more ring for your pound or are they all much of a muchness?

- Is there much value in buying used (don't like the thought of a ring being previously owned by someone else, tbh).

Asking for a friend.