Debates about cost of manufacture, ride quality, and parts availability aside; Bromptons are very good value in pure financial terms. They depreciate very little, and sell easily on the used market. In this sense, they are some of the best value bikes on the market.
Of course, this has absolutely no relevance on if you'd enjoy the bike relative to other brands, but at least you won't take a major hit if hate it and want to rid of it.