A little help please....

I have been reading on this forum for a few weeks, and could use a little hand holding...

I have recently bought an 05 X5 4.4 for my wife. The navigation unit doesn't seem to be up to par. I am assuming the previous owner never updated the system to current available standards. I have seen in several places that version 32 is available and it should cost around $16.

I went to our local dealership today, and asked for the update CD for our X, and was the appropriate DVD is $199. I was obviously shocked and instantly knew I was not completely clear on what I needed.

The part number the guy told me was 65 90 2 241 695

My question now is... what exactly do I need to do an update on our system? Our current system shows SW 4-1/50 on the screen.