How important is sitting behind a load balancer?

My project was designed to run on one server. It keeps some images it stores directly in a directory and keeps the addresses of those images in a mysql database. 

How important is it for me to be running multiple instances behind a load balancer? 

I don't expect to ever get to over 50 users. The system is not very CPU bound, except when it is running a report, which can take 6-8 seconds to run. 

How important for the success of the project is it to be able to run on multiple instances?

proof that an old dog can learn new tricks