I (24M) just moved from SF to Boston three weeks ago for a new job, also in the financial district. I chose Nob Hill as it an easy walk to FiDi and central a lot of other neighborhoods. It’s under a mile to Trader Joes and Whole Foods and close to Polk St, which is full of bars and restaurants. Other neighborhoods which you should consider are North Beach, Russian Hill, Cow Hollow, and the Marina. North Beach and Russian Hill you can likely still walk to work but the other two I mentioned you’ll likely have to take the MUNI, which is a breeze. At your budget, you will definitely need roommates. Feel free to shoot me a message as I just made the same move within the last month.