For the load balancer solution, a lot more is needed then to just rent a load balancer.

Example: What do you expect to happen when the server with your DB goes down? Just send the next UPDATE/INSERT/DELETE to DBserver2? Which is replicated from the DBserver1? When DBserver1 comes back, how does it know that it now is outdated and has to sync from DBserver2? How does the load balancer know if DBserver1 is synced again and ready to take requests?

Even if you set up all moving parts of your system in a way that handles random machine outtages: Now the load balancer is your single point of failure. What do you do if it goes down?