MySQL to ionic 2, with or without REST APi

I have two options to connect my database

  1. Save it to MySQL, using php, then connect to ionic (convert to json format via angular js)
  2. create REST API, (from backand or apigility) connect to ionic

I need a method that is easily to scale up next time but also lower cost when the traffic is high in the future.
Initially I prefer to use as they have MySQL, but they have limit to 30 request /second for total API created, so it may be costly in the future.
If I use option 1, I worried I may have a hard time when I want to add more database.

Sorry, I will pass this to a vendor, but I will do it by myself once i need to add more databases.

Which option is better for my condition?