It all depends on the use case. In our case the choice is like this:
1. With LiteSpeed
a) One powerful, multicpu server: $600 a month
b) LiteSpeed License: ~$90 a month for 8 CPU license
2. Without LiteSpeed
a) Two powerful, multicpu servers: $1200 a month
b) Apache: free(but most likely will require someone skilled to tune it, as there is no easy to use configuration panel, so additional spending is required)
So for us, it is like saving $700 per sever a month