If your CV isn't making noise then just replacing the boot is all that is required. Your friend is almost right in that you'll be quite a ways into replacing the entire axle assembly but if you use the MechaTech installation instructions in the Download section, you'll only be about 60% of the way to axle replacement rather than 90% like he's estimating.
The other factor is $$$. Axles are expensive if you can find one at all. A set of 4 boots will only set you back about $150. Even if you find a set of used axles, you should probably replace the boots anyway.