Hi collinsfarrah,
The better options and possibilities in and around the San Francisco/Oakland area I’m aware of (subject to the quality/value guidelines here) are listed in post #2 here. If you are in the southern East Bay area then the San Jose list in post #2 here may also be helpful.
Your budget is significantly higher than you will need to buy a very high quality mattress and I would keep in mind that the price of a mattress doesn’t necessarily reflect the quality or the materials inside it.
Phoenix