The first SpaceX block 5 booster was flown on May 11 and it is scheduled to be used again for a launch on Tuesday August 7. This will be a slightly less than three-month turnaround. SpaceX plans to shorten the turnaround time for block 5 to less than 24 hours between launches. Elon Musk plans to try a fast turnaround in 2019.
Block 5s should be able to withstand up to 10 flights with minimal refurbishment between missions and up to 100 with moderate work. Older versions of Falcon 9 were only reused for two flights.
Previous Falcon 9 cost $60 million to launch but the Block 5 only cost $50 million.