Azure Load Balancer is free of charge but is not offered with Basic Virtual machines.
Public load balancing
Every Cloud Service gets a free public load-balanced IP (VIP). If you want to load-balance on multiple VIPs, you can get additional VIPs at a nominal charge as outlined here.
You can assign up to 5 additional IPs to your Load Balancer.
Internal load balancing
Load balancing between virtual machines that reside inside a virtual network (Internal Load Balancing) is free of charge. Adding additional VIPs to the Internal Load Balancer is currently not supported.