Yes, you can find a 3 bedroom home for under 350, however its a limited selection, and generally the homes tend to be older in Miami Beach. Is there a specific reason you are looking on the beach? There are great neighborhoods nearby that will give you more for your dollar that are still minutes away from the beach.
No matter where you choose, either will provide access to equally good shops, restaurants, and stores.
Please let me know if you have any questions, or need help with anything else.
Platinum Worldwide Realty
786 253 4577