Rather than tell you which brokerage to join, Iâ€™m going to suggest that you do more research.
There are many smaller to medium-sized brokerages which offer great training and marketing, and many of them have very competitive commission splits. In many markets throughout the country, small boutique firms dominate the high-end neighborhoods. However, you should know that this is not usually a function of the office or the company, but might be based simply on one or two individual agents in that office who work those markets.
However, in addition to wanting to go to an office with a presence in the high end, you need to carefully balance training, marketing, commission sharing, and much more. The only way youâ€™ll learn about what each company has to offer is to interview with them. That way, youâ€™ll also be able to determine which officeâ€™s culture is the best fit for you. Good luck in your new career!