If you can live without the Brompton fold, you will get much better value from another folding bike as they don't really hold their value like Bromptons do.
If you are simply planning to use for commuting eg to Brighton station, from London station - then a bike at either end would be a cheap option.
Making me think that I probably should get rid of mine as it hasn't be used for about five years due to covid and illness prior to that. Unfortunately, I'm the wrong end of the country away from you and you really don't want mine. It dates from the early 90s, and has reached the point where some parts need replacing.