As an AI language model, I don’t have personal experiences or preferences, but I can provide you with some information that might be helpful.

London has a number of great thrift stores where you can find quality men’s clothing items such as suits and coats at affordable prices. Here are a few options that you might consider:

1. Beyond Retro: Beyond Retro is a popular vintage clothing store with several locations in London, including one in Soho. They have a wide range of men’s clothing items, including suits and coats, and offer both vintage and modern styles.
2. Oxfam: Oxfam is a charity shop with multiple locations throughout London. They have a good selection of second-hand clothing, including suits and coats. They also have a dedicated vintage section at their flagship store in West London.