Hi All - Apologies, new to BA Tier world - currently need 90 points to make Silver by end of Sept 2024. What is the cheapest most efficient way to do this? Based in London. Using the AMEX BA Platinum Plus card.

I have a trip booked on economy to Budapest in April, looked into upgrading to Club but that would only get 80 additional points for the additional £500 odd ( as I would need to upgrade myself and partner obviously)

Any advice?