Pros
If you don't come from a traditional consultancy or outsourcing background, and want to develop a career as a consultant or contractor then Buying Team is a great place to start. Irrespective of age or experience on paper, there is an expectation that everyone will take responsibility for the quality of service delivered. From a personal perspective this means that you will quickly get exposure to how client organisations operate at a senior management / board level. You will also learn about a wide variety of generic tools and processes that can be applied to any type of organisation to identify savings opportunities and achieve 'quick wins'. Once mastered, these aspects will genuinely help you to fast track your career. If or when you decide to move on you will be in a strong position to take advantage of the many opportunities for senior roles.
Cons
High turnover of staff. Creates a negative impact on staff moral, but anecdotal evidence also suggests that this is building a poor market reputation amongst both recruiters and peers. For consultancy salaries are on the low side of average. Compared to operational purchasing the money on offer may seem slightly above average. Either way, not great for a company based in Central London. 3 month notice periods can be good for job security, but are tough on junior people that might feel they need a move but aren't at a career level where a potential employer will wait that long. Internal promotion seems to be based upon the urgency caused by people leaving rather than being based on merit. Most major clients are based outside of London, so expect a lot of UK travel and overnight stays.